When do you consider Batwoman to have started the SJW takeover? When the character was brought back as a lesbian in like 2006? Because sure, I could see that argument. I remember though that Marvel was trying similar things at the same time, but they were worse at it. Batwoman's revival was considered to generally be a well made comic. Meanwhile Marvel brought back The Rawhide Kid as a big flaming homo. But really, yeah, there was a bunch of similar shit at DC, like killing off Ted Kord and replacing him with a mexican kid. But people at least liked the mexican kid, and the series didn't shit all over Ted Kord and say that he was never a good Blue Beetle to begin with. Marvel is the company that went all out with it starting with Carol Danvers completely changing personalities once she became Captain Marvel, and then they replaced almost all of their high profile characters with affirmative action hires that were also smug assholes, just like the writers. Meanwhile, DC was specifically doing DC Rebirth to reverse a bunch of the changes they made a few years earlier and bring back the more classic elements. DC at least sucks bad enough to flip flop on their SJW bullshit. Marvel goes all out with it.
But let me be clear, they're both awful, and both have been evil, soulless corporations from the start.