Of course there is. We have no border security. That's a problem.
Everyone who wants in, gets in. Right? If they're willing to wait their turn they might.
Where's the guarantee the US will allow in any and everyone who wants to come? It doesn’t exist. So those who don't want to try through legal channels should ignore the law end enter anyway? In your world, apparently.
You're the one who said that we allow in plenty of foreign workers. That it just takes time. Now you say they can't get in. Make up your mind.
The day we allow enough foreign workers into the country that there is no demand for more of them is the day that illegal immigration will end. Not one day sooner.
Those who do not understand this don't understand capitalism and market forces.