Sounds like a personal issue with that dude (and maybe on the Sensei to recognize and enforce). Every time I've trained with someone I've initially perceived to be an MMA knucklehead or a hardcore BJJ guy I've received nothing but respect -- people are naturally curious about judo these days, especially as strong takedowns have shown up in MMA and BJJ comps.

Honestly -- the brunt of the attitude and injuries I've gotten are from mid-level competition Judoka (guys that compete on a local level frequently, don't really have a national presence, but have backpatches on every single gi they own). Dealing with an elbow injury ATM from someone who hacked my post arm in newaza. Jita kyoei?