I don't see this as looking for constructive reform for, as an example, better conditions for H1B residents who have no mobility or leverage. Its saying "Stop H1B and stop foreigners from taking our jobs". If thats not their message, I don't know what is.
Anecdotally I have previously worked at Wall Street banks that used "Body Shops" with fixed term contracts to fill positions that otherwise Americans could fill. It's awesome working with smart people from over the planet, but the system needs to be configured in such a way that it does not undercut American wages. Companies need to be able to seek out specialized talent that they cannot find in their own local market, but it is abused so much that it cannot continue in its current form.
There is such system for cities in China (Hu Kou) and it's a nightmare.
I think for me, the line might be around protecting against transience. IF you want to join my community, people who are looking to contribute and leave a lasting impact should get benefits over people who are there to make money and leave. But there isn't really a great way to monitor this.