The thing is, it's human nature to want to do the 'easiest option' for the 'least expenditure'. But as you said, doing so loses a lot of enjoyment by queuing automatically. In my small FC we don't usually do full group events as we simply don't have enough members to do so - so instead if anyone wants to join we preform a party and enter via the DF, thus it fills in the missing spots, so we still have the sense of friendship while not having to find fill-ins manually (such as CT).

And of course, it doesn't need to be said that there is absolutely nothing stopping you from manually forming a party and then physically heading to the dungeon entrance and entering via there - it's just far easier to simply enter via DF.