SegWit transactions take less space, are chaper and SegWit block is max 2gb. SegWit allows lightning network that makes transactions extra cheap and fast. We don't need any other increases in blocksize, because we have to keep bitcoin decentralized and runnable at any home PC. So we have to save space. The issue is the precedent, not the 2MB increase. Miners cannot be allowed to hard fork without the users' support. 2MB may be fine but if we accept the precedent, then we'll have 8/16/32MB blocks soon, and maybe eventually inflation.