You seem to heavily underestimate these dudes
If you don't think of them as complete idiots (which they ain't), you should expect that they have calculated everything well enough to be certain of success. Why would they want to fork off if they weren't going to succeed? Further, they are not going to attack Bitcoin directly, they have artfully managed to make users pay insane fees, so what makes you think that they won't be able to beat Bitcoin into oblivion, which is what they will do? Many if not most people here are exclusively for profits, and if they see the original Bitcoin crashing, they will be eager to sell their coins for this new Bitcoin (whatever name it might have)
Maybe I am, but China is basically a Bitcoin desert outside mining. The actual usage is taking place in areas where the economic players have nothing to do with mining and Coinbase at least is having nothing to do with this fork. I assume most others will follow.
They've consistently proven their code isn't good enough. No one other than themselves wants to follow them.
The big block advocates, or rather this strain of them as I don't really have a problem with larger blocks, seem to operate in something of an echo chamber of their own construction.
I think they rather radically underestimate the utter contempt most others have for them or there's some weird blindness to it. Check the average Roger Ver tweet. There's a list of abuse about four metres long beneath it.