A few comments. I'm a software engineer and I am very _pro-immigration_. This view point seems to be held pretty consistently among my colleagues (although certainly not universally). I am not pro "open borders"; that's different. I'm not sure all the exact data behind the assumptions in the question, but I can comment on why I am in favor of immigration:

My experience working with a lot of international people (H-1B, etc) is just that in general the people I have worked with have been highly-motivated, hard working, and fantastic people to work with in general. Bringing more people like this into the country I think is just good for society and good for the culture. Any statistical disadvantage it may create for me (salary-related, job competition, etc) I am just not concerned about. I think these concerns tend to be overstated.