As a US citizen, I can't agree with you more. We have perceived immigration issues, because millions of people have entered on foot or otherwise across the southern boarder without stopping at an immigration station to register. All because there is so much money to be had from performing manual labor compared to any type of employment in many so called Latin American countries. This, of course, is illegal, because laws were enacted to keep undesirables out of the country.
So at the same time, a law that is ineffective in discouraging people from entering without legal documentation, discourages many who would normally immigrate with complete authorization because the process is too cumbersome and limited. I personally don't know what a better process would be, but contribution the non-black-market economy is good for everyone, in the end.