OK, I suggest that you stop looking at this situation from some sort of idealistic perspective. The thing is that American President and Congress are serving interests of Americans, not foreigners (H1b, green card holders, etc). They have to find a delicate balance between what to give foreigners to please their constituents (not just people but also companies who have powerful lobbies).
American universities are interested in foreign students because they can pay a lot of money for the opportunity to study and then have some time (a year or more) to get a job in states. Most Americans fret at the idea to let foreign graduates (even from US universities) to compete for the same jobs with American-born graduates (I already hear: "our own children cannot get jobs after college, why let foreigners to compete!"), however this is part of the deal: allowing them some time to get employed here makes this student visa more attractive. Read: they will be willing to pay more to study. Good for American universities.
However, giving them 5 years of time to get employed or start a business? In the eyes of most Americans this is beyond reasonable. It's going to create a major outcry and will not be voted by Congress. The only situation it's going to work is if America had a population shortage and needed more people (like Canada, Australia), but this is not currently the case in America.
Now let's look at American businesses. They are interested in skilled but cheap labor. And H1B gives them exactly this. You call this slavery? I agree, up to some extent. But these people are foreigners and until they become citizens, they have no voice and are effectively nobody. So, it's their price if they want to be in America and eventually become 'somebody'. Sounds harsh? Correct. We live in the world of conflicting interests of different people, not in a paradise. Don't forget about this.