It looks like you're part of Core. This does give me a better idea of why you're opposed to it, though Core probably should voice their reasoning more publicly. To me, Core seems to be rather secretive and little is published about them in the crypto media, which is what most in the crypto community follow and all we hear is that Core is opposed.
"Core" is a group of developers. We aren't exactly social people nor are we affiliated with "crypto media". They tend to not write things about what we are doing even though virtually all discussion happens in the open. It is not that "Core" is secretive but rather we produce little content that the media can capitalize on to make stories (i.e. not much interesting stuff comes out that journalists can understand and write stories about; we don't have press releases or anything of the like) as nearly all discussions are technical in nature. Furthermore, "Core" is not an entity; it is not one cohesive thing with an opinion. It is made up of several individual developers who happen to work on the same thing. Very rarely does "Core" produce something unless nearly all of those individuals agree on the same thing and agree that it should be published. However "Core" has made their position very clear on 2x and this blog post:
https://bitcoincore.org/en/2017/08/18/btc1-misleading-statements/ details what everyone in "Core" generally agrees with.
Could you elaborate on this some:
it is well known to the developers that there are many issues with larger block sizes which 2x does not address
The quadratic sighashing issue, although limited by a 1 MB tx limit, can still cause large blocks to take even longer to validate (on the order of several seconds, which to computers is ages). The memory blowup attack which, although is an implementation problem, AFAIK the fix is not present in btc1 (the segwit2x implementation). It is also not known whether the network can handle 8 MB blocks (that is what the effective maximum block size would be) and how that would effect block orphan rates and full node count.
Who can we expect to be the developers for the Segwit2x chain if Core stays on the old chain?
Jeff Garzik.
If 2x does somehow succeed, then most Bitcoin Core developers will quit Bitcoin entirely as 2x's success would mean that miners and companies can have absolute control over what Bitcoin does. Bitcoin would no longer be decentralized and be something that miners can change on a whim.