I agree with OP, not being able to pick the game mode(s) you want to play has made trying to find a good game a bit like playing Russian Roulette, with most of the time you're not going to get the mode you and your friends wanted to play, to the point of some giving up and wanting to play a different game...
Having a checkboxes for all the different modes you're interested in playing like before was a far better solution as then if you where ok with playing any mode, or just some, you could check the ones you wanted to play and if it was only one mode, then you had the option of only looking for that one and not being forced to play a mode you don't enjoy, which as I said before, can easily result in players quitting the game.
Please go back to the old system or something similar so you can choose which modes you want to play. Thanks!