How can we improve our answer acceptance rate?
As I write, there are 18,677 question on MP&T with at least one positive-scored answer, and there are 9,978 questions with accepted answers: a rate of 53%. (Looking at total questions, the acceptance rate is 50%.) I haven't found health metrics for graduated sites, but for beta sites, according to How were the guidelines for a healthy site determined?, 90% is considered healthy. A personal acceptance rate of 70% is suggested in (the accepted answer for) How does accept rate work? Taken together, that would suggest we're subpar.
The "helpful" bar for accepting answers strikes me as both very low and very reasonable. So either we're not very good at providing helpful answers, or we're not very good at accepting them.
Related: Why is our engagement rate low?
Now that there's been time for initial comments, some reactions.
Accepted answers with negative scores
There are 24 such answers on our site. That amounts to 1 in 400 accepted answers or 1 in 833 total answers. That small ratio seems like something we can live with.
User acceptance vs. community voting
Both provide important metrics. Community voting gives an indication of the overall quality of answers. User acceptance gives an indication of whether individual users are being helped by the answers. A "helpful" rate little better than a coin flip does not suggest a useful q/a site.
It's true that most questions come from less experienced users, and the acceptance rate is also lower among those users.1 All the more reason that the more experienced users should set an example both by making a point of accepting helpful answers and also by helping the newest users understand how the site is intended to work.2
The importance of acceptance
To suggest that acceptance is being treated as "so important" is to set up a straw man, and to suggest that reputation gain is an important motivation denies the basic design of SE sites. The point here is only that acceptance of answers has importance.
When searching for information, an accepted answer helps narrow the field. "This question has at least one answer that was useful to the asker." A searcher would be more than justified to prioritize questions with accepted answers over others.
And when looking for questions to answer, the reverse applies. A question for which a helpful answer has been supplied would rightly attract less attention than a question for one which has not.
It's easy to point out pitfalls in both approaches, but this is inherent in all SE sites. Questions may be incorrectly tagged. Wrong or low-effort answers may be upvoted. Titles or keywords might not turn up the needed result. Nevertheless, all have their value, and when well-maintained by the community, they make for an effective system. Responsibly improving our acceptance rate is one way to increase the value of that particular SE feature.
1Users no longer registered account for 3.7% of total questions with an acceptance rate of 46%. Users with Reputation below the Established User privilege account for 75.7% of total questions and an acceptance rate of 48%.
2Among Established Users (Reputation >= 1000), the average reputation is 4877. Users with a Reputation >= 1000 and < 4877 accept answers at a rate of 62.8%. Users with Reputation above 4877 accept answers at a rate of 56.3%.