I don't like Scott Snyder's Batman in general, I thought Metal lost a lot of steam as it went on, and I absolutely hated The Batman Who Laughs mini. Plus I already hate everything about Scott Snyder's Joker.
His origin is the cheapest cop-out you could possibly have to come up with a Batman/Joker combination, everything this character does is shit like >"And then I corrupted the Teen Titans! And then I committed tax fraud using the Batcomputer! And then I made all those orphan zombie Joker-Robins EAT THEIR OWN PUPPIES WHO WERE ALSO ORPHANS AND THEN ALSO YOUR FAMILIES HAHAHAHA"
all the time, and as is, he's this uber-competent menace who knows all of Batman’s darkest secrets and doesn’t really make all that many jokes. There's pretty much nothing that sets him apart from how Joker is already written nowadays other than his admittedly great design and his connection to Dark Multiverse shenanigans.
He is nothing more than a cynical cashgrab, just another big bad Scott Snyder pet character and the new "Ultimate Batman Villain" that they put out every decade, and I hated just about nearly everything I've read with him in it.
But I genuinely can't bring myself to hate the guy. I mean, sure, there's his design, but not just that.
Maybe it's because I don't think he's going to stick around for long and they'll just replace him the next decade with a bigger and edgier villain, and he does have potential.
If only because, with him around as the uber mega threat whose appearence constitutes a capital-E Event, they could maybe free Joker to once again be funny and a regular Batman rogue, where as BWL is the guy who shows up every 4 or 5 years to burn everything down.
Or hell, I can think of pretty funny ways he could be used for comedy in non-Joker ways. I liked how he was used in Death Metal, cracking meta jokes at his overexposure and other things. That could work.