Unfortunately, on average they are seen as cheap replaceable work with no resort to taking abuse. However, amongst them there are quite a few very talented developers. If the system worked properly they would be able to select them better. I work with quite a few H1Bs and the experience has been quite pleasing. However, I can see the abuse they take, the unpaid overtime they put in, because they can’t say no. That may spoil our market and we would soon need to fall in line with them.