How are you quitting jobs w/o 2 weeks notice and not being screwed?

I notice a lot of posts about people quitting jobs with no/little notice and I wonder how?

Any job/company worth its weight uses a 3rd party company to check past employment so I can't just leave a job off my resume. They would definitely notice and definitely call them to see if I was rehireable. That company would say "No, they are not rehireable" because I didn't put in two weeks notice.

So either these are kids quitting entry level jobs and it doesn't matter OR these people are screwing themselves in the future? right? Am I missing something?