Then why did he specifically suggest that we do so?

He limited the block size to 1mb in 2010 and knew fully well that a hard-fork will be needed to change it.

This is not true. SegWit itself claims that it enables "off-chain transactions". Those violate the definition of Bitcoin. SegWit is not compatible with Bitcoin by definition.

It enables it. You don't have to use it and can continue doing all your transactions on the blockchain.