I thought this was a really interesting issue! I get why Steph's characterisation may be divisive, so forgive me but I'm gonna rationalise it - or at least try to.
Tynion's made it quite clear that he likes Steph best as Spoiler, or rather, the Spoiler that was written by Chuck Dixon and Jon Lewis. Cass is his fave batgirl, and he's made mention before how he liked Steph's role in the batfam as the girl who was always on the fringes and never fully included in Bruce's crusade. He probably didn't want to write a repeat of Bruce not trusting Stephanie and it backfiring spectacularly over and over again since it's such a tired (and I would argue a wee bit sexist) plotline for her, so instead he went with her actively working against them. Kinda. Dixon and Lewis' Stephanie was a perfectly sweet girl with a stubborn streak a mile wide with a temper to match. She closed herself off when she went through emotional turmoil and became reckless and self righteous when angry. Stephanie, when secrets weren't kept from her, was endlessly understanding of Tim's problems but needed help working through her own, though for a while she didn't understand that and wanted to prove she could do it alone. I think it's the exact same here - only this time, the one person who could help her (Tim) is actually the cause of all her pain. (On a side note, I do feel like a lot of Stephanie's conflict could be resolved through one conversation with Dick, who understands Batman better than Bruce does sometimes, but, alas, I do not think that conversation will ever happen.)
I like the angle that both Stephanie and Bruce are doing what they think Tim would have wanted, Stephanie with the more victim orientated approach versus Batman and co.'s more expansive crime fighting approach. I kinda want to see a scene were Tim sees what has happened in his absence and just kinda face palms at it all.
The point is - Stephanie's not necessarily acting out of character here... I get why people prefer her Batgirl characterisation, since she's more easily reasoned with and has a much more level head whilst being funny and sweet and all the things we love about her. But this is still a Steph which is inherently optimistic. She believes that humanity is capable of thriving without vigilantes, that everyone in that group is capable of achieving a more stable and happy life. I'm not sure she understands that it may not be as fulfilling a life for them however, and is a gap in her thinking which she'll have to deal with in her own time.
I was worried when I saw the spoilers for this issue - I seriously thought Tynion finally messed up - but I thought the execution, Bruce's conversation with Kate especially, showed that Bruce greatly cares for Steph, and he will hear her out at every opportunity she choses. What she's doing is not malicious, and that was what I was most fearful for, so I'm relived that she's doing it out of the belief that the people of Gotham are better than what the others think. Her optimism is going to blasted to pieces eventually in some upcoming storyarc probably, but I hope she comes out of it still hopeful as ever. It's still 'There's Room For Hope In Gotham' Stephanie, just one that's exerting it in a different way.
On a sightly unrelated note, I let out a small 'oh noooooo' at Tim and Stephanie's snapchat image. How sad! And then, I let out an even louder one when Tim was looking at the same photograph! The shipper in me died a little at the fact that she's his biggest motivations to escape. *Shakes fist at sky* Darn you DC! Let them go to college and have a mini-series of their (ft Cass ofc) shenanigans! We've had plenty of high school hijinks, let them go to college darn it!!!
Anyway, I don't know if any of what I wrote above changed people's minds about the issue, but I hope that I explained well why I thought it was an interesting issue. The villains certainly could have been a bit more compelling, and I'm still waiting for Cass to have a bit more to do in her own arc, but I really felt for the team, and am ready for Batwoman's solo to bring in the new year!