People leaving battlegrounds is a big problem. 15min deserter is enough on x1 server where you are actually punished and can't reenter another one. On high rates and instant 80 realm you can just leave and enter with another character. It often leads to situations like during a single WSG match 30 people leave from one team and the starting team size is 10. That means majority of the battlegrounds you join are already started and losing. That also leads to people playing more premades that are mostly armed with bunch of holy paladins and shadowmournes. Playing battlegrounds alone became a real nightmare recently and joining a premade isn't a real solution because you just absolutely stomp and graveyard camp nonpremades all the time. Which leads to even more ppl leaving and more premades playing etc.
I suggest making battleground deserter account-wide. 15min deserter just doesn't work if you are able to get multiple 80s in no time and just leave the game if your team is starting to lose.