Because miners are realizing that its more profitable at the moment to mine BCH. Investors are realizing that the 8mb size is actually working. And 90% of the hash rate is run by ONE organization which makes it easier to P and D.
This is the correct answer.
The price rise means it is now more profitable to mine than Bitcoin. And on Saturday around noon, the difficulty drops again, making it even more profitable to mine
The next stage depends on the miners - are they going to maximise proftability? Or endure losses because they love Core?
Adding to the drama is the fact that most alts are based on scrypts, so ASICs can't really mine. Bitcoincash is the first major alt that uses sha-256 which means that at last bitcoin miners have an alternative...