I really do not understand why the "core team" has a 2X problem.
Without 2X is not Segwit. Bitcoin has exponential support, so 2X is a good compromise.
Well, they never really agreed to Segwit2x. They implemented Segwit, which had widespread support. The miners and services decided amongst themselves to hard fork 3 months later. Discussions of the 2x hard fork itself aside, I think it's reasonable that both Core and users generally oppose such a timeline.
... ok I understand that they want to create a "market fee" and "birth of side chains" as soon as possible.
The war between Bitcoin and Segwit2x will damage both sides and finally 2X is necessary (only the of time question)
The way I see it, the damage was already done. Maybe not for the same reasons as others think so, though. To me, the fact that BIP148 folks (now NO2X folks) wanted to permanently split Bitcoin so they could activate Segwit a bit earlier tells me they don't share my long term interests. If anything, it was an attack on my interests as a holder. Likewise, hard forks -- particularly contentious and hasty ones -- similarly threaten my long term interests.
There's a lot more to gain in terms of consumer (cheap) payments, anonymous payments, smart contracts and more if we are just patient and allow developers to build on top of Segwit.