How do you provide feedback to the people that work for you? How does your company review employees? Do you have a cyclic review period tied to compensation? Does everyone scramble around every 6 months or so to collect and deliver evaluations of each employee? If so, I feel sorry for you.
If the people you work with every day aren't providing you feedback daily, then they have no right to show up at the end with a list of could-haves and should-haves. What kind of teammates hold back any information that truly would improve your behavior? The progress you make to improve is something that doesn't happen with a summarized list once or twice a year. It is a daily grind that demands you get unflinching, constructive, and contextual feedback from your peers, your leaders, and your subordinates. Anything less is just an exercise in whining and collective finger-pointing.
The same is true for customer feedback. Customers tell you when you aren't behaving as they would like. If they don't it is because they recognize other forms of value you might bring. Or they ask you to leave. They vote with their pocketbook every day. Just because someone has rough edges doesn't mean the customer doesn't see the value in that edge. Now mind you, I'm only talking about singling out individuals here. Success as a corporation or on an engagement basis still absolutely requires that you measure their satisfaction at intervals, and definitely seek engagement feedback with post-mortems and such. Even with your peers and teammates these are good practices. The point of those exercises is to collect information corporately, meaning "as a group" or collectively. It allows the aggregate experiences, the sum of the value-exchanges, the result of the processes and approaches to be refined and improved. They can't successfully be used for isolating out individual performance if for no other reason then the ineffectiveness caused by the time-delay and lack of context. What was uncomfortable or outrageous in one context can be completely justified if the delivery priorities are met. You have to examine the parts as they relate to the whole, not independently. You can't separate the means from the ends, even if they don't always justify each other.
When it comes to personal feedback I would go so far as to say that if you have feedback to give someone and you don't provide it in a timely manner, then you are the more at fault. Consider how we excuse the behaviors of others around us all the time. There may be some aspect of the context, the value-exchange, or their behavior that balances things out. There may be something there in the moment, at the time you noticed the behavior that allowed you to see past whatever negative things you'd like to complain about. Maybe you emphasized with the situation at the time, or made allowances because you noticed other positive side-effects. As you watched the reactions, maybe you agreed with the messages or appreciated someone else's unique predicament. Or maybe you were just lazy. But if in the moment, when you noticed the behavior, it wasn't significant enough for you to speak up, then you can't bring it up later and beat them over the head with it, out of context. When you no longer have the balance of the empathy, or the clarity of the context, you can't assume you are really being objective. Was the intern rude to interrupt your meeting, or did he save you thousands of dollars by catching a costly mistake just in time? Was voicing objections to a potentially bad decision a good idea, or inflexibility? It may be that she is defending her decisions because she is self-serving, or perhaps she realizes that not speaking out now will open a door for future liability? As any good consultant will tell you, the right answers always start with "it depends".
All of this is not to say that it isn't possible to notice trends over time. Sometimes behaviors are subtle enough, or we are lazy enough, that we need to see the same patterns repeated before we notice the effect. It may have to occur several times before we have enough data points to take umbrage. This is very realistic and understandable. But still we must realize that that at some point, you did know. You became aware and cognizant that the latest data-point was the one that showed the pattern. You witnessed the latest exchange, you noted the recent behavior, you said to yourself "they're doing it again". It is at that moment, that you have a choice. Give the feedback, or store it up as ammunition to blast them with later. My suggestion is: don't be a punk.
Of course, just because I think feedback should be frequent, contextual, specific and time-sensitive doesn't mean I think you can interrupt processes, dialogs, or other exchanges just to give that feedback. I am not ignoring or dismissing the necessity of propriety and appropriateness. Sometimes you do need to set something aside so that progress can be completed, so that events can unfold, and this is fine. The trick is not to let things go. Don't let them fester and build up with time. Find (or make!) time to engage that person and encourage them with what you have noticed. If you care enough to give them feedback, if your feedback is meaningful enough that you expect it to be well received, then it needs to be delivered swiftly and surely. If it is something you can wait months to tell them about, it probably isn't worth spending the time on. If you can't be bothered to help them alter their behavior by giving them feedback right after the meeting that went so poorly, then it must not have been so earth-moving that it needs to come up again at review time. If your feedback is truly impactful, you owe that person a chance to show that they can take your feedback and apply it. If it was just anecdotal or just your opinion on things that might somehow in some subtle or subjective way make them more "successful" (whatever that means!), then you surely can tell them in a forum that won't adversely affect their salary and standing.
In my mind, your compensation should be appropriate for the value you bring the company, not fluctuating to the randomness of some subjective standard. Getting evaluation feedback that helps you improve should be an every day occurrence, not a special event. If you only get a few special events they should be encouraging and uplifting. So if you want to use an evaluation result as a reward or incentive, then direct it for that purpose specifically. Linking it with personal development improvement items sends too many mixed messages and often only reinforces the bad behaviors and laziness of managers unable or unwilling to invest in their individuals.
Does your organize only provide for evaluations at milestones that are spread far apart? If your role requires that you review others, perhaps you could try to focus on and celebrate the positives. Use the special occasion to encourage and build up, rather than tear down. There will be plenty of time to talk about how they can improve at a later time. Like tomorrow. And the day after. And the day after that.