Are you saying that working all sorts of overtime, taking on extra projects, etc., isn't going to help you get a bonus or possible promotion?
Didn't say that...said if you failed on projects, most likely adding in extra isn't going to help much and you will be fired. I'm not talking about people who fail one test and are 0.5% away from an A for the entire year, I'm talking about people who are 0.5% away from passing at all. If I failed on that many of my projects, "extra credit" isn't going to help those projects.
I guess in school extra credit might help the child learn something that would otherwise not be learned but in real life, extra credit in the case of many failures would not work well. Again, if it was one failure in many projects (i.e. a B+), sure, extra credit (taking on an extra project, especially on your own time) might help.
I can definitely say that if you fail a customer (at least in my business), you generally don't get a 2nd project no matter how much extra you do to make the 1st one right. If it's a long time customer, maybe but generally, no (I've seen this first hand on 2 projects in the last year - not my screw up so I didn't get dinged (Son of the owner so I don't think he got dinged either)).