Are we sure that the search for credit and for approval does not infect the ego of the users of this site?
I think the credit and approval system does what it's supposed to do: highlight the best answers to a question. The fact that it inflates the ego of some vain people is not the problem of the moderation system: it's the problem of the people's vanity. In the same way we don't blame on cars the fact that some people drive dangerously.
You cannot blame a tool for what people make of it. A tool is not good or bad, it's just suitable or not.
In a gamified system like SE/SO reputation and score is a source of motivation.
In a Buddhist context, this can be both:
- stinginess as to one's gains (Lābha-macchariya) - in this case, gain in reputation
- stinginess as to one's status (Vaṇṇa-macchariya) - in this case, total reputations accumulated
But for this system to work gamified element is essential as this is tied to the privileges on getting on the site. Also, votes and acceptance can guide people who are not very knowledgeable in Dhamma to finding better answers. So one should vote on and accept answers which one sees as being in line with the Dhamma and downvote on ones which seam not being in line with the Dhamma. (Use this sparingly as it might agitate users.)
In the real world giving something has merit as it is useful to others. In this system, one can give to questions and answers as bounty. If one is attached to reputation then this may help reduce macchariya. But a better way is not to be bothered with the reputation gains. If you are mentally not attached then this will not hinder the achievement of Jhana. Having said it is better to put bounties more sparingly to questions which might attract great answers which are useful to the spread of dhamma. Also awarding a bounty may be en endorsement that one agrees with the answer and it is in line with the Dhamma. This should not be left to the system alone. People without much knowledge can use this to distinguish what is in line with the Dhamma and what is not using this as a cue.
To summarise, votes, accepting and bounties serve a purpose, even in spreading the Dhamma. One should explore how this works for oneself and use it wisely so that it aids the spread of the dhamma signalling to other users about the correctness and acceptability of what is being said. Also, look at the system like a hammer. If you are using it there is a particular way to use it. If you do not hit with the head it does not work. So try to put the system to work in a way which benefits the dhamma the most. This being backed by good volition would also mean positive karma.