The question in the title is misleading. Because what Core think, and what Core and Blockstream want you to think and believe, are two entirely separate things.
Recently Bitcoin Core developer Luke Dashjr (aka Luke-jr) wrote an opinion piece almost entirely about "Bitcoin Cash" itself.
But before we get onto the Bitcoin Cash topic here, let me address one glaring point made by Luke early on in his piece. Given that Segwit2x is well underway now, Luke actually makes an admission – stating, and I quote "Basically, BIP148 (UASF) was an early success". This statement conclusively reaffirms statements I made in an earlier piece that Blockstream (UASF) and DCG ( Segwit2x) are in bed together. And I'm going to restate this – big blockers have been played.
But Luke's ponderous post is genuinely a marvel in deceit. He bewilderingly states that "Bitcoin Cash" is an altcoin, and that it is an attempt to hijack Bitcoin.
This play on words is all too common within the Blockstream camp. The hijacking came from Blockstream and no one else. But to help illustrate this point, allow me to paint this picture. Suppose you are part of an open source project. You release a founding paper specifying your project's inner workings, methods, and overall operation. Your project is unfunded, but passionately developed within an open, transparent, thriving community. A new company emerges, and cleverly makes its way among your development team, and receives an incredibly large amount of funding from some very big players in the industry. This company then starts to weed out some of the early developers of the project, and particularly those who don't agree with the company's very distinct vision.
Discussion and promotion of the original founding paper is prohibited. This company then (for argument sake let's just call it Blockstream) rewrites the project to a vision that is incompatible with its original founding paper. So then in retaliation a small group of people, some who were there in the beginning, come together, and re-launch or rather see the continuation of the original project with the original intention, following the original founding paper.