I don't care about the merit he's earned, the rank he's achieved, or who chooses to employ him, but this:
Why is he on DT?
That's a good question. I don't see how he's made himself trusted enough to be on DT1.
That's probably more a consequence of the rotating DT system than anything else, although obviously he got enough inclusions to make it in there in the first place. Whether or not he deserves to be in any level of DT, as long as he's not abusing his status I'm fine ignoring him being on it since he'll probably rotate off eventually.
I read some of the thread that accused him of plagiarism, but from what I've read from everyone else he didn't actually plagiarize anything--hence he wasn't banned. So there's no reason to beat a dead horse, because unless someone can find evidence of him actually plagiarizing something without citing any source whatsoever, mods aren't likely to do anything.
Has Ratimov done anything else shady? Getting into a squabble and name-calling doesn't count in my opinion. Anyone can get into a pissing contest here and still be trustworthy.