I don’t think they are, they’re just worried about what might happen if Amazon brings down the ban hammer.

Please don’t ask leading questions like this, they’re not helpful to the discussion.

Is he not allowed to?

It seems like somebody like you has to pop in and imply (accuse) a commenter of being anti-labor or whatever, whenever it's pointed out that unions can have downsides.

Unions have upsides, and downsides. Discussing them helps people make good decisions. Pretending it's all flowers and rainbows does not.