And to be really honest, even if you don't have time (i am one of those), you can easily join a pug from LFG and if you spam invitation you will get inside (if you have a decent ilvl, and with WQ and mythic dg is really easy).
Once inside it's like a lottery, like any other matchmaking system game: if you are LUCKY you will clear it, if not, just try again.
I don't really get all those complains.