There are two (very disjoint) opinions that both land in the same place (banning/restricting open-weight models).

1. "We want to own it and be the only megacorp that exists in the future", and

2. "Proliferation of open-weight models is like giving everyone a nuclear reactor in their home: it is extremely dangerous to the world"

Anthropic has previously stated (or, at best, implied) that they believe/have-reason-to-believe the second.

Some other organizations, well the public has every reason to believe they believe the first.

The end result of "hardware shouldn't be capable of running non-validated models" is the same between the two.

I can't comment on which of the two Anthropic is (because I have literally never in my life talked to anyone in an influential leadership position there). Just keep in mind that even people who are diametrically opposed can have matching recommendations (again, for polar opposite reasons).