People think that a fork is imminent. First of all, none of the big pools are going to switch to producing bigger blocks until they have at least 51% of the hash. Probably a lot more. The way BU works is that it will eventually go for the longest chain. If any of the big pools start mining bigger blocks with less than 51% of the hash, they'll end up mining a lot of orphans. You think they are that stupid?
All the core team needs to do is introduce a block increase as well as Segwit and everyone will kiss and make up.