I recently got an accepted answer in a category, but no upvote and I noticed that it does not reflect the score total on the specific tag. It looks like you only get a point in this score for upvotes. Should accepted answers get a point in this score like an upvote?
No, I think it's fine. It's rare, but you can give an accepted answer that isn't helpful.
In the vast majority of cases accepted answers come with upvotes so it doesn't matter for them.
It also prevents people from accepting their own answers and gaming it.
I had this several times with newbies that did not have enough rep to upvote.
On SO there are 10005 pages of accepted answers and only 8765 pages with upvotes accepted answers. That leaves us with around 18600 accepted but not upvoted answers (at 15 answers per page). I think this is more relevant then one thinks.
But I do think that counting them as if they were upvoted blurs the picture. Yes, there is the rare case of an accepted but useless answer, and there is the maybe not-so-rare case of the questioner accepting an answer after a while to get the 2 points, get the reminder of his user page to accept one or start a bounty, or just get the question off the unanswered page.
Even though there seems to be a case here, I would leave it as is.