I mean I think there was a very clear path here and it wasn't as glamorous so of course the politicians and gov't workers ignored it.
Path 1: Replace Amfleet, AEM7, and Acela 1 with off-shelf Siemens or Bombardier equipment such as Railjet-like trains. No tilt, 125MAS, all coupled cars. Some of them are streamlined into HST look-alike and marketed as Acela 2 premium service (bigger seats, better food, limited stops), some are less-streamlined and marketed as Regionals. Replace a lot of catenary. In 20 years you are ready to run a real HST.
Path 2: Buy a bunch of HST that can go 150 in a few places, but you really only run 90 and 125 because the catenary is bad and MNCR owns a long stretch of the route.
I have acquaintances that ride for business. They ride Acela because their peers - high income bankers and lawyers - also ride Acela. They do this because Amtrak successfully marketed and advertised it as a premium bullet train. But they don't know who made it or how often it goes 125 or 150. It's a bit of an emperor new clothes situation. If you streamlined an AEM7 and Amfleet set, put connoly leather seats in 1+1, wilton carpets, served Dom and Filet daily, THEY WOULDN'T KNOW THE DIFF.
Amtrak is proud to announce a new train to Florida that doesn't stink: The Floaterian. An all-star just like Babe Ruth.