Are people really like this?

[Final-Fantasy]

And how exactly would they know what platform you're playing on anyway, you could say anything and they wouldn't know, but really who is going to join a group with that kind of attitude from a recruiter.

They will only know once you are in the instance if it's cross world. When you exam people's gear, if they are PS4 players, it shows their gamertag in the bottom right corner under the job stone.

True to a point, though if you're playing on PC the gamertag doesn't display to PC users, it only shows up for other PS4 users, so they couldn't tell if they are playing on PC to begin with, they would need to be on PS4 to see who else is playing on PS4.