The other part is that at-will goes both ways: you can just walk out of a bad job with no legal repercussions. Not always the best idea due for social/professional ones, though.

That argument is definitely BS, though.

What do you think happens in the most restrictive labor market in Europe? We're not slaves. There is a short notice period, usually 1 month or even shorter (notice periods for companies are longer, usually double or longer).

And if it's a bad job people just phone it in, take medical leave, etc during their notice period.

Hardly the end of the world to last 1 month.