Thats true but I've seen HL players with buildings that require more collections per day.
Also, night clubs can be easily hidden behind hotels and other buildings.
Being the best income producing building in the game even if you collect twice on a level 10 nc it still beats a level 10 casino.
Moreover, it may not be possible to collect 4x in 24 hours but not that difficult to collect 4 times in 30 hours.
In the long run it will average out most likely north of 3 collections per day. However a 24 hour or 48 hour building can be even more problematic. Even though you collect once a day or in two days all you need is to forget to collect or something comes up to throw a wrench in your collection. Trying to resync collections on these building will be quite difficult if you time things just before your bedtime and have now pushed it back another 2 hours for instance.
On the other hand 6 hours for a nc is a breeze even if you miss collections.