Not that there's anything terrible about Segwit, it's just that we already have better solutions for everything it claims to do.

For instance we have a solution for the transaction malleability issue - Flexible Transactions - which causes a tiny fraction as much technical debt while offering big benefits in future-proofing. Why bother with Segwit when we have a better solution?

But that's neither here nor there because Segwit doesn't even solve the actual problem that everyone wants fixed right now - block size. The small, one off, slow to deploy solution offered by Segwit isn't a scaling solution at all. It's likely that take-up of Segwit wallets will be fairly gradual which means it'll probably never even prevent the blocks being full. Even if it does we'll be back in the same hole in a few months time anyway because of the small one off change. What's needed is a solution which actually fixes the problem.