Segregated witness has been around since 2015 with good publicity and proponents since early 2016. It seems to have the benefits of solving transaction malleability, creating a good foundation for the Lightning Network, implementing script versions and most importantly a temporary transaction scaling solution.

Is the main reason for the slow miner adoption (https://coin.dance/blocks) because it means lower transaction fee's for them? And is a soft fork being avoided because a hard fork is preferred?