Some people defends the lack of answers by saying that PJ didn't want answers, just revenge.

That's complete bullshit, this serie isn't a third person view following PJ all the time, it's done in an omniscient way.

We've been onlookers from a God perspective so we deserve at least SOME answers, not just the answer of some pointless explosion in season 6.

Face it, the writers showed their incompetence by not being able to tie the loose ends. Heller has been hiding behind other writers that have gone on a rampage. Now he couldn't clean up the mess.

The main problem is the general audience of TV-shows, they are not demanding / involved / intelligent enough. Therefore crap like this is accepted as a valid ending. 

The same thing happened to the game Mass Effect 3 but then the fans were vocal enough to demand a better closure and got it. I doubt the same thing would happen here though...

Maybe an apologize from CBS for the leak and a japanese style public appearance for the writers where they can hang their heads in shame while asking for forgiveness.

Pick up your hayforks, people!