So I joined a team...

For me it's a combination of the size of the henchies plus the godawful noise they make. Bots and Demons are bottom of the list when it comes to MM team mates. I wouldn't quit, unless they're also useless but I would tend to switch character /build to a ranged one to save me some grief. I like teaming with Zombies though. Say what you like about the evils of Necromancy and summoning corpses to do your bidding but they are very well behaved corpses

Mind you I was trying to play a Widow during City of Demoos so a lot of it is down to residual scarring from that.

Making Henchies walk-thruable by any team mate and quietening them down a bit would solve a lot of problems in that regard.

The complaints I'm seeing about MM pets are why I follow a few simple rules of etiquette:

1) When exploring a mission map, I do so from behind my teammates. This keeps the pets behind my teammates as well, making them less likely to clog doorways.

2) If I must summon my pets, I'll find a clear spot away from teammates and park them there until we're ready to move. If there aren't any such spots available, I'll wait for everyone else to move out and catch up with the rest of the team after I've summoned and upgraded.

3) If I am not in a mission or engaging an enemy, I do not have pets active. I summon them upon entering a mission, and dismiss them before hitting the exit button. My primary is summoning combat pets, not hosting the freaking Rose Day Parade.

I stand by what I said on the very first day Demon Summoning went to open beta: demons would be a lot less annoying if they were about 2/3rds their current size.