We'll have a blocksize increase after segwit. It's not Core's fault that miners are fucking stupid and are not signaling for segwit as soon as possible. Segwit is needed before we increase the blocksize.
Segwit
provides a blocksize increase. Putting that aside, I would welcome a properly written HF proposal that builds upon Segwit. However, I would not be willing to accept something that reduces the block size limit (as proposed recently by luke-jr).