All your saying with ur OP is "split up casuals and hardcore players". Get over it man. Casuals aren't going to go through the trouble to search through the party finder for a party. Duty finder is RANDOM and honestly i don't feel much of a tie to the other players i encounter in them because half the time the dungeon will complete without a word being spoken the whole time. How bout if u wanna be all elitest about it form YOUR OWN PARTY so u can make sure to only recruit the "perfect" players to fit your play style.
I just hope u understand lots of new people are flocking in from ps4 and also people are beginning to come back to check out new 2.1/2.2 content (including myself). You should seriously get over yourself. The more people that learn these encounters the more people there will be to fill up parties for true endgame. Everyone has to progress and some don't like to rush as much as others.