I think it's a mix of both. We have a new association of players that's founded with zero women in it despite having women in action behind the scenes. Why they didn't sign, why they weren't included from the start, that's irrelevant for the fans, journalists, anyone. The fact is they're not founding members. The fact is the 'first-class' of the association is a picture with 50+ players, all men. Those facts alone don't look good.
Some people are talking about it from a place of genuine concern about the lack of representation women have in sports, and that's valid. For them, it's not about trashing the PTPA for the sake of it, it's pointing an issue that's real, an issue that lead to the ATP and all its tournaments, players, etc. treating women's tennis as something less: not considering them from the very begining. Seeing them as 'well, they'll follow after we're done with the preparations', expecting them to have no voice on how to build it.
And from that valid criticism, of course the opportunistics will come. Obssesive fedal fans, or people who are against Novak and just want to see this fail, they will take a real issue and use it as a flag to undermine a good movement. I'm certain some pro-ATP media/journalists are taking it as an approach to talk bad about the PTPA as we speak. Articles with that sentiment are already out.
Which leads me to my biggest issue with the PTPA: how undercooked everything looks. 'Cause if they have been working a couple of years, or maybe just even months on this, they should've seen this coming. They're going against the ATP, a gigantic association that has a huge part of the sport in its bag, that's going to do its best to keep things with the order it wants. Why risk being portayed as 'anti-women' or whatever they want to call it when they could've just reach out from the beggining to Serena and Sloane, get some women to work with them from the start, and avoid all of it?