Sure guys who just want to have fun can waste the time of the guy who wants to gig and make money. But, it can also go the other way around. If you have a bunch of guys whose main goal is just to get together and jam, and there's a guy who wants to spend time on promotion, booking, learning dance tunes, etc. the "pro" is wasting the time of the "amateurs" by trying to get involved in stuff that's not in line with their goals, which is just to cut loose and have fun. I quit a band like that because I realized, I was wasting their time as well as mine.
Many times, time wasting is a result of a misalignment of goals and priorities. That's why it's always best to put your cards on the table.