It cost billions to build a high speed train network and the Federal as well as State governments can't afford it right now.
We invented the airplane and air travel is our mass mover as well as an interstate highway system and 175 million cars and trucks moving us. China hasn't many airports, nor do they have many paved highways. High speed rail is cheaper for them right now.
Also in Europe, most of their railroads were bombed out in WWII, so they rebuilt for higher speed and more safety over and under roads. Our infrastructure wasn't damaged. Eisenhower built the interstate highway system, because we made more cars than anyone after WWII. We already had an extensive rail system. We were also the largest aircraft manufacturer after WWII so we built more planes. We have not only more commercial planes than anyone, but also private planes.
Most American's also like the convenience of their cars when traveling long distance, like a days ride to somewhere. If it takes more than a day we fly. Also if we are in a hurry to get somewere, we fly. High speed rail is only good for trips less than 500-600 miles, this takes 3-4 hours by high speed rail. You can drive it via interstate in 6-8 so why train. If it is over 500-600 miles you either fly or drive 8-12 hours in a day. High speed trains would at least have to stop at every major city, so that would make the 3-4 hours even longer. Say I wanted to travel about 1,000 miles from Montgomery, AL to Milwaukee, WI (my wifes old hometown). We drive it in 14 hours rotating. Say you had a 200 mph train. You could go non stop in 5 hours, but it would have to make a stop in Birmingham, Huntsville, Nashville, Louisville, Indianapolis, and Chicago. (I'm not using a straight route for the train because if would have to connect larger cities). Ok if you only stopped for 15 minutes in each town along the way that is another 1-1/2 hours. The train would have to slow down and speed up at each stop, so that probably adds another 1 to 1-1/2 hours. Now you are at 8 hours, and since it is taking 8 hours, now you probably have to stop at least 1 hour for every one to have lunch, unless meals are served on the train? Now we are at 9 hours, and we drove it in 14? Why a high speed train?