Especially when in season 1 he made it sound like he put all his money in the bar and it was barely staying afloat.
shareIt's a sitcom. There are going to be plot holes. The plot is just a way to get to the jokes and laugh.
shareMore of a social life living with a roommate. Also, from what I've seen, upstairs isn't much of an apartment and would be a bit lonely. Finances aside, that's my reasoning. Edited to say, wait, didn't the gang all pitch in to become partners and help him financially??
shareThey dropped the financial partner thing after Season 1 as well as renaming the bar and calling Justin "Baby Bird" every episode. All good changes IMO.
As for the room upstairs, it's not really determined how much of an apartment it really is since they show just the one room and it's not that nice at all and quite small. I wouldn't want to live there if I owned the place. As for him living with Danny, that's a plot device so we have more reasons for Danny and Justin to argue and get into mischief. It's the Odd Couple part of the show where as the bar is the Cheers component.