There is a more fundamental argument here, before you even have to go to economic specifics.
The capitalist critique on Chinese HSR is pretty trite as well as expected. China is building bridges and trains to nowhere, huge projects that run at horrific efficiency and will never return the investment.
This is a pretty common misunderstanding on how things work or should work in a society. In the capitalist West, these projects are made for profit. The companies that build them are supposed to get their money back, and then keep exploiting them until the heat death of the universe. The state is there to serve them and their investors, not the people that those projects are supposed to help.
In an organized society that is trying to reach socialism, these projects are made to serve the common good. Direct and indirect economic benefits of infrastructure and mass transit are well known, studied and welcome. Projects are indeed designed in a way to be as efficient and cost-effective to society as possible, and there is competition, innovation and rapid advancement in all aspects. BUT, in the end all economic arguments are simply secondary to the obvious benefit those projects have on local communities and the country as a whole.
One builds for capital, the other for the people.