I am among those who would like to see Amtrak upgraded to track speeds and frequencies that would be useful - those of 1950 spring to mind. I have heard that it wouldn't take all that many billions to do a reasonable upgrade.
I personally see no use for "bullet trains". Having driven large things at 300 mph, there is just no way I want any part of a train hurtling down the tracks at speeds like that. Eighty is plenty - maybe 110 on the straight parts.
Not sure where you heard that. As most folks know, the speed problems with Amtrak primarily stem from the fact that they have to use infrastruction that belongs to the private freight railroads, and guess who takes priority? It's not a matter of upgrading Amtrak's track speeds and frequencies - freight schedules effectively keep a lid on it. Not sure what a "reasonable upgrade" would be, other than adding more dedicated track for Amtrak's use, but that cost would be enormous.
Don't want any part of bullet trains? China, Japan, and Europe are leaving you in the dust. And the U.S. air system is becoming saturated. Now what? Then there are those who think the U.S. is "too big" for high speed rail. Really? China soars while America sleeps.
"Beijing-Shanghai high speed train link the two megacities 1,318 km (819 mi) away in just 4.5 hours. By 2018, China keeps the world's largest high speed rail (HSR) network with a length totaling over 29,000 km (18,000 mi). The world's longest HSR line, Beijing - Hong Kong High Speed Railway, extends 2,440 km (1,516 mi)."