Pretty simple really the community has been clamoring for a block size increase for years now and the devs have been actively fighting it. They managed to create enough division in the community to scuttle the last compromise (Segwit2x) and now people are rotating en-mass to Bitcoin Cash which has the larger blocks they want and doesn't have the divisive developers.
Very little surprising about this at all except for maybe the speed with which it is happening.
>>now people are rotating en-mass to Bitcoin Cash which has the larger blocks they want and doesn't have the divisive developers.
This isn't entirely objective. BCH has 25% of its market cap trading today in volume. There's something weird going on. As for the developers, BCH has very little Github activity while Core is being actively worked on and improved.
I don't have a horse in this fight as I am into other cryptocurrencies but your statement is not very fair.
Very little surprising about this at all except for maybe the speed with which it is happening.