vendors can't get away from middleboxes, because Enterprise customers want middleboxes. But if customers want a completely reinvented underlying technology, everyone is forced to either adopt it or become obsolete themselves.

This whole middlebox obsession is some kind of Stockholm syndrome. Here you are telling me there's people who make shitty devices that don't respect network traffic and because of that you can't change network traffic. It's like saying there's someone breaking into houses to steal stuff, so we can't install stained glass windows because a thief might break them.