"This is my playstyle" is a poor argument for being bad.

[Adire]

Never said I'm OK with people being lazy or intentionally slowing down a run. Now, it could just be that the person honestly does not know any better. Perhaps they're a BLM who leveled purely from fates, and has no FC. That could be a good time to give some tips. People aren't born perfect gamers.

Not directly, no, but this bit:

OP, if you're concerned about how people play the game, you should play with only your select group that you know will be skilled enough. Few things to keep in mind:

-Some people enjoy different things in game, and just having fun in dungeons (even if they include wipes or silly mistakes) may be part of this

Sounds an awful lot like you're faulting people who expect some semblance of effort rather than people who don't feel like putting any in. The people who expect people to pull their fair share in a TEAM effort are not at fault. The people who have no problem with turning a normally 20 minute dungeon into an 80 minute dungeon and justifying the problem causers are. You shouldn't have to make a static to do casual content just because one person in DF has fun screwing around and putting the group through that, that person is at fault. The 4 people are put into a group to work as a group, not to go into lone wolf fun playground mode.

Not to mention, someone who has fun wiping and making silly mistakes is someone who isn't going to push themselves to be beneficial to the group. Part of improvement is having the desire to improve, being overly tolerant of your own mistakes during happenings like this is counterproductive. If someone has fun being deadweight and detrimental to the group, they need to leave and re-evaluate their mindset and try again later when they've actually taken into account that not everyone is there to waste time and not everyone has the time they may have to waste.

I'm sure I'd have fun playing badly, watching TV while I play or just doing it for laughs, but I'm not going to. Because it's more fun actually pushing yourself to see what your best is at any given time and more fun not being detrimental to your group and being "that guy/girl" that single handedly extends the run by 40 minutes because of a lack of care and sense of self importance.

Oh, and a BLM who levels off FATEs but hasn't figured out how the job works will need more than some tips from a random in DF, they'll need to go back to square one to learn everything from scratch. The Paladin I had in Snowcloak who was unstanced, not using combos, not using flash, only RoHing one mob comes to mind. He was beyond our help and on top of that called me an elitist for advising him to go back to early dungeons to learn the basics after attempting to explain why he should combo, flash, etc. That's why you should make sure you learn the basics of your job while leveling.