Nope, Kill Stealing in MoC is not bad, the only time its bad is if ur stealing the kill from ur teammate. In MoC, its the best way to make sure u get more points and the other person doesnt.
Edit: Well I think ppl can cuss u out if ur not even fighting and just watching the fights until a person has one hit left and u take it, thats pretty much the only thing that I think is wrong.
Surprisingly, I entered MoC often times yet I didn't get hate messages for killing enemies alot with my hammer have tiny AOE movesets.
I did got a hate mail from 2v2 team for stealing kills once.
Isn't MOC basically...
All Free Kills Buffets?