If this is the case, why are they forcing them to sell specifically to a US company rather than any non-Chinese company with less draconian laws (EU, etc).

If "free access" were permitted, these Chinese companies would surely be absolutely crushed by their US counterparts and its citizens would forever be consumers of US goods while forever providing the cheap labor to produce them.

To build self-sustaining growth, a country must establish the positive feedback loop of consuming its own goods.

The latest big move in that direction was the new Foreign Investment Law https://en.wikipedia.org/wiki/Foreign_Investment_Law_of_the_... that went into effect this year, which introduced a bunch of big changes, such as switching from the previous system of "everything is off-limits to foreign investment unless explicitly allowed" to "everything is open to foreign investment unless explicitly forbidden". That list of restrictions http://images.mofcom.gov.cn/wzs/202006/20200624143734575.pdf already includes provisions for further opening in the future, such as removing the last restrictions on manufacturing passenger cars by 2022. (Special-purpose vehicles, electric cars and commercial vehicles are already exempt.)

If that doesn't demonstrate "intention of opening up", I don't know what would.

The only thing about China that hasn't changed seems to be Western commentators' knowledge of it.

I feel like if you were to replace China with Europe your statement would still apply for the software sector.

China has only recently become a big enough economy in their own right to say "nice try but no thanks" to US driven international law.