The devs should dev, stay neutral, and stay above the fray. Stop raiding the cookie jar of free stake. I know it is tempting to use it but exercise some self-control please.
Not only does it put the Steem dev team (aka Steemit) team in a position of picking favorites and represent an illegitimate use of the ninja-mine (which was supposed to be for funding purposes and not be used for stake voting except in cases of emergency) but when things inevitably goes wrong (this isn't the first time and it won't be the last) it blows back on them, and therefore onto Steem.

If Steemit weren't involved and dmania were doing these things with its own money, it might be a case of abuse (not even actively doubting it, just using uncertain terms here because I didn't analyze the 'proof' carefully), but it would just be one other user, of many, who should be perhaps be downvoted (whether that actually happens enough and what should be done about it is a discussion for another day).