I just got out of my 3rd interview this week and every single hiring manager has done this. They'll ask me what I do currently, I respond, and then they'll trash it hoping I agree with them about how bad it is.
Today's example that made me want to write this was me interviewing for a security company as a guard.
Hiring manager: what do you do currently
Me: flagging/traffic control
HM: Oh yeah I bet that's awful work just standing around all day in the sun or at night
I can see right through you, I know you're trying to get me to agree that's it bad so you can weed me out immediately or see what attitude I'll have about the work I'll be doing. Why can't you just ask me? Just ask “oh well security has a lot of standing of around in the elements, does that bother you at all in your current form of work?”. I'm not stupid, why do you have to try for the subterfuge?