1) The 1.7 figure is outdated, the latest one from a research by BitFury in November 2016 is 2.1MB [0]. It's probably somewhat higher now. Yes, it does require wallets to upgrade - but most of them (and all of the major ones) already have segwit implemented [1]. In addition, once a few of the major players that produce lots and lots of transactions upgrade, the fee pressure will level down for everyone, even these who did not upgrade for SegWit.
Yes, it is a one-time increase, but one that is sufficient for now. Let's start by doubling the block size first, collect more data, then decide how to further increase the blocksize as the need arises.
2) I'm not seeing that they're going against the community. The technical, business and wide bitcoin community are all looking forward eagerly for segwit's activation.
Edit: also, in the case of a hard-fork, users who don't upgrade gets cut off the network entirely. is it not preferable to keep them a part of the network, with somewhat higher fees but a functional wallet otherwise?