I dunno, I don't really see it except in crap parties or when we get a troll healer that likes to let the tank's HP dip lower than they're comfortable with a PUG group. Personally I distrust anyone I don't actually know. As healer, I assume tank don't know shite about their cooldowns, or DPS are gonna do something stupid in the time it takes me to blink, so I keep it above 75% (dip toward 50% to avoid overhealing, but neeever below that). As Tank I assume I've got a nitwit healer watching netflix. Too many time I figure "naw it's fine, they'll use bene aaaany second now... right?" And then I die because my cooldowns were long gone and they weren't paying attention. :P

I understand why people actually good at their jobs would feel offended, but you gotta understand these people don't know you from a hole in the wall. There's enough horror story experiences to explain why they don't trust you.

Basically: don't take it personally lol.