Here's the thought process:

1. it was really hard to get into this country
2. if we make it easier to come here, that nullifies the work I did

A similar argument applies to a lot of other things, for example:

• student loan forgiveness - I paid my student loans (or worked to avoid them), why should others get a pass?
• mortgage assistance - I saved to be able to afford a home, why should others skip that step?

A lot of people attribute this to selfishness, but I think it's closer to jealousy. I have two kids who share a bedroom, and if I reward them equally for cleaning up when one did 90% of the work, that doesn't seem fair to the one that did the most work, even if they're older and more capable. I think that's pretty similar to what's happening here.

That said, I personally am in favor of much more open borders, and I'd like to get to a point where we don't have quotas or anything and people can come as they please. My ideal is a quick stop at the border to fill out a form (i.e. temporary work authorization), then perhaps monthly digital reports about job status, and then a longer-term authorization once you can prove employment (or at least financial stability). We have a huge backlog, so in the meantime I'd like to simplify the paperwork and increase the quotas until that backlogged demand is exhausted.