Compatibility with off-the-shelf European & Asian designs is a good long-term goal, but pursuing it at all costs from day one -- even if it means having no service at all to areas where brand new separate tracks don't exist -- is financial insanity. By all means, build any new track to HSR standards, and build towards the goal of a totally separate network 25-40 years from now. But don't throw the baby out with the bath water, and build an initially-useless HSR line to use as a metaphorical gun to the head so you can use it to threaten financial suicide if it's not completed down the line.
The madness and insanity of the original California plan was the fact that for the first decade or so of the system's existence, it would have had direct service to NOWHERE besides cities in the Central Valley. Somebody riding from LA to San Francisco (the primary market driving it) would have had to change trains twice. At that point, it's not even worth BOTHERING with separate HSR trains in the middle, because any time savings would get completely nuked changing trains at both ends.
It makes *infinitely* more sense to build HSR-grade tracks in the middle, connected DIRECTLY to the existing rail networks at both ends, and run Acela-type trains that can run everywhere along the line... slowly in LA and SF, quickly through the central valley. Then, as funds permit, the new tracks can get built to replace the shared ones, until the glorious day when the FRA-compliant trains can be sold off and replaced with EuroHSR trains. In the meantime, passengers have 40 years of coherent service from San Diego to San Francisco & Sacramento that starts out as "good", and gets better and better every year.
If funding dries up, at least there will still be a good, viable, working rail network in place to use until funds are available again. That's *infinitely* better than a scenario where you end up with abandoned, never-used infrastructure (or worse, borderline-useless infrastructure with high ongoing maintenance costs, like a HSR line that literally runs only between Bakersfield and Corcoran).