Ah heck, even Melda productions does AAX... it can't be all that hard. :-)
It apparently really is a PIA. Not because of AAX specifically, which by all accounts is well-documented and well-supported. Rather, it's because of the new requirement - and a new third-party software dependency - to have Pace digital signing implemented in every AAX plugin.
What that means is you get a little piece of Pace copy-protection magic bundled into every AAX plugin, whether it uses iLok or not. It means nobody can write an AAX plugin that doesn't have Avid's official blessing, because you need a special tool from Pace to generate the signature and they'll only give it to official Avid developers.
Avid would like very much to do away with the small independent software developer and leave it all to the "Pros". They're reportedly (developers are expressly forbidden from discussing this) charging a $500 annual fee to AAX developers to license the Pace signing code, a significant hit for the bedroom coder who only makes a couple grand a year off plugin sales.
Somebody wrote an AAX wrapper that would allow PT users to use any VST plugin. Avid killed it immediately, since they have a built-in kill switch to disable any plugin they don't approve of, and the terms of the SDK license say they don't need to give a reason for doing so. Avid does not appear to be putting users' needs at the top of the priority list.
I'm so glad I never went the ProTools route. I have an acquaintance who went with a full HD rig 10 years ago. He was pretty pleased at the time even though it cost as much as a new car. I wonder how he's enjoying his gold-plated boat anchor today.