“And they warn that banning Americans from downloading Chinese open-weight models wouldn’t stop their proliferation — but would weaken U.S. startups.”

Well this doesn’t even make sense.

Weaken U.S startups = Can’t legally develop commercial products that use or remix the latest open weights models in novel/creative/cost-reducing/etc ways, while companies from the rest of the world could (including China, who this is ostensibly supposed to be punishing)

Wouldn't stop proliferation = Despite that, your non-programmer 14 year old child can still install the latest Qwen model on Day 1 by copying a one liner command they got from a YouTube short that sources from a Gitlab repo outside US jurisdiction

It does because corporations, especially smaller ones competing with bigger ones, actually do get prosecuted for violating restrictions like this a lot more than individuals do.