The only "tiptoeing" I feel is when I get into a group and there's someone who is legitimately terrible, and I feel like I can't say anything. Few times do I speak up and give pointers. In those situations it's usually met with silence, a thank you or the rare "YOU DON'T PAY MY SUB" bullshit, at which point I just put them on ignore and say, OK buddy, initiate a vote kick for harassment and move on. It's VERY rare where it's SO bad that it becomes frustrating though. Many times it's just a "well, this player isn't very good" and the dungeon takes a few extra minutes, which isn't that big of a deal to me.
On those rare occasions though, like @
Wrecktangle and his famous Shield Lob only Paladin story, the entire group is commenting, telling them to go look at a guide, to stop wasting other people's time and if (usually not "if" though, lol) they get aggressive and lippy about it they end up getting kicked for harassment and are replaced.
As I said though, those situations are extremely rare for me, I only do maybe 2-4 dungeons in a day through roulettes and only for leveling. I don't usually do the Experts, as I just don't care that much about end game gearing, just about having a high enough gear level to do the story related dungeons each patch.