I don’t think UDH-direct mount derailleurs are a terrible thing TBH. Don’t get me wrong I’m normally a ‘standards skeptic’ but the whole point of UDH is that punters now have the ability to source a common mech hanger from anyone, not have to pay an extortionate sum for some wonky stamped bit of aluminium that ceased production 5 years ago.
As for being forced down the SRAM route? Well you could still buy a UDH hanger and stick any conventionally mounted mech you like on there it’s pretty much the opposite.
The ‘standards’ imposition that worries me most is flat mount, if you start seeing that abomination on MTBs get worried (anyone get close-up shots of the other chainstay?)…