If Bitcoin splits into two, due to the blocksize issue, I think China will have a lot of influence over BU, but I think the other chain will keep its properties, and probably a larger number of users, at least that's what the number of nodes indicates.
I don't think if there would be a hardfork there would be plenty of people moving to the new one. Even if those hardforkers want to move to a new crypto, there are more people that wants to stay with bitcoins. So even if they try, they will not overcome the status quo of bitcoin. It will also not affect the bitcoin market, I think.