On the East Coast you’d need to exercise eminent domain to make it work. As it so happens, a high speed line would run through a lot of seriously wealthy neighborhoods. These are the wealthiest and most politically-connected areas of the country.
On the West Coast, you have A LOT of big mountains and rugged terrain, the likes of which you don’t see in the Northern European plain, and also, some other seriously wealthy (and NIMBY) neighborhoods. There are a lot of people who resisted building the BART through the peninsula and Marin. Caltrain’s already got people suiciding on it all the time, and they needed to build the high speed line through it. The commuter infrastructure isn’t really there.
Well, you may get your NY to LA route because the midwest area is quietly building out their passenger rail capacity for their own needs and desires. Everything they are doing is discrete, incremental projects that have an attainable budget and timeline. They are using normal rolling stock so speeds are limited to 110mph, but they are laying the groundwork to allow for faster speeds later on.
To be fair, it was Chicago to LA ;) https://en.wikipedia.org/wiki/City_of_Los_Angeles_(train)
But hight speed rail down either coast, why not? You'd share the same infrastructure as slower commuter trains, have large towns from N to S to stop by, and surely there's a market for people who want to travel in comfort from Seattle to SF.