I noticed this the flashing messages on SO when downvoting question to please let a comment or flag to "show what's going wrong" (not cited but I think you get it). I couldn't see that this is depent from the reputation. Okay as I can enter the first review queues on SO I also have enough reputation to comment but I can't imagine that this is relatied to the users reputation.
I never noticed a flashing message like you mentioned about remembering people to accept / upvote answers. I would like to see more accept / upvoted answers on SO and SQA as well (the only two sites I'm in).
Espically more accepted answers would help the SQA site. According the SQA-Beta Overview at Area51 we could improve at this topic. Main problem stays the content but this is on another page - especially in such a specific topic like SQA.
I think the main "problem" of many SQA-questions is that they are broad and based on experience like "What shall I do to improve my QA carrer". We have less "fact based content" like SO. Sure we have many selenium questions about how to "programm" this or that but we also have many indiviually questions where people ask for adviese. If they can create real solutions with these, like convincing management to use tool XYZ, is very complicated to identify.
For myself I have this question about automation tools for GUPTA applications. I didn't upvoted or accepted any of the answers because all tools didn't help me to solve the problem - because the problem seems to be part of GUPTA/Windows itselfs and not by the choice of the tool. In the past I already thought several times of deleting the question because of that but then decided to let it open as it got five upvotes what shows me other users are interested in that topic too. But will I ever get a working solution so I can accept this answer? I doubt about that.
If we here on SQA would move defintion questions to a "wiki" (like the announced documentation feature on SO) and also putting those "what tool can I have"-like questions together our content would be much more less.
So yes: Any option to improve the acceptance of answers would help this site and I found many interesting things here so I hope we will get out of the beta at some day.