This really does bias the types of immigrants we get. As much as people might complain about immigrants coming in and then going on welfare, it just doesn't happen with any frequency. Instead, we get immigrants who come here and start companies at twice the rate of natural born citizens.
Our labor laws also select for people who really want to work - at least compared to our European counterparts. I don't mean to say that people who emigrate to Europe don't want to work, but the perception that you have to work longer hours in the US certainly does weed out the people who are overly concerned about working too much.
As long as we continue to have people who want to come to the US, I can't see why we'd want to make the process easier unless we can continue to keep these filters in place.