I could see where hot coals in a tall building could be a hazard, let alone a huge pain in the rear to dispose of. That said, char-grilling is so immensely superior to propane that the end results aren't even in the same universe when it comes to flavor.
I made it a priority when condo shopping to ensure I was on the 1st floor of the 3 flat so that the grill could be on the grass plot between the building and garage and thus not run afoul of any HOA guidelines. Given that the building is self managed, inviting the other 2 officers of the HOA over regularly for beer and brats tends to build favoritism towards one's charcoal-heavy agenda as well. Bribery, that's the Chicago way!