I went to an Alter Bridge meet and greet on the Last Hero tour and while they weren't really rude or anything, they did give off the 'couldn't be assed' vibe. Even when we went through and got stuff signed one by one, they were pretty dismissive I felt. Scott especially was quite blunt and hardly looked up and didn't even ackowledge us when signing. I was fine, because I couldn't imagine doing those night after night.
There's no excuse for someone to be an asshole in a meet n greet. These are the most loyal fans paying extra money for this service. It makes the actual concert a sham, honestly, if you can't bring yourself to acknowledge your biggest fans. It's not like they're accosting you at the store.
As someone who ran a record store for nearly a decade (and witnessed some pretty appauling behavior by way of entitled artists via meet&greets), I could not agree with this more. No excuse, man. I'll be honest, being on that side of things a few dozen times with some pretty big bands, the way they treated me, the guy who was grabbing their water and talking to their manager, made a huge impact on what I thought of them.
To that end, one band that sticks out in particular is none other than Disturbed. I am NOT a fan, at all, but David Drainman was beyond gracious and professional. This was well into their career, they were a HUGE band, but that dude acted like it was the first meet & greet he'd ever done, and it made all the difference with the fans. To this day, I give their new record a spin whenever it drops...respect-driven curiosity.