Its because Segwit by itself isn't going to scale very well, at least not in the short/long term. At some point we WILL have to hardfork or Bitcoin will die, plain and simple. The masses won't care that about all the legacy nodes, they won't care about any of the technical marvels that make Segwit an amazing upgrade. They just want low fee transactions. Even with Segwit, a 1mb block will hinder Bitcoin's transaction capabilities. But a 2mb legacy block + Segwit? now THATS something that can scale, and with scale comes more adoptions, more usage. And with adoption and usage comes price increase, because Bitcoin will still be scarce and it will still be secure. So with this NYA, Bitcoin will have a future, and it will be a bright one.
Or on the other hand, everyone can call each other names, label each other as the enemy and keep the community divided while I go and invest in some altcoin that has a brighter future because their community is not crazy yet.
either way works really