This is because H1-B is the "only" way for an international fresh grad to work in the US. This is a direct result of US immigration policy which ties up the visa process with the need for an employer sponsorship and more importantly the ability to acquire permanent residence is also tied up to employer sponsorship which leads to "indentured" servitude as many folks around here point out. Compare it with let's say Germany who has a "Blue Card" visa program which gives an international (or intra european immigrant) 18 months to find a job and then if you manage you work for an employer for another 22 months (only) you get a permanent residence. This does not need any sponsorship from the employer. It's just a clock. Same is the case with Canada and Australia.
All countries which attract foreign students in their universities give some sort of a time period for them to use the acquired skill and if prevailing conditions are right, to stay in the country and work. Imagine you want to move to Germany, what will you do? A) Search for an employer sitting in the US and hope they file a Blue Card for you (equivalent to getting an H1-B filed from outside the US) B) you plan to study and then stay there based on your studies (OPT leading to H1-B in the US). Now if you study at University of Erlangen and immediately after graduating you are told you pack up your bags and leave, then what do you do? You can institute such a policy saying no international students will ever get to stay in this country, then it's fine. The only thing would be a tremendous drop in in coming students who are also paying through their noses and investing dollars into the University System. That's how it works worldwide.
The problem here is most of the people here do not understand what Visa options are there, how they work, what kind of extreme vetting takes place to get a student visa in the first place, most folks would have never ever applied for a visa in their lives, would have never seen the inside of a consulate, would not know how visa systems work in the rest of the world and then arrive at a conclusion which is based on shaky foundation.
H1-B visas are not only for Tech, they are also for other streams of education or workers like MBAs. There are two kinds of complaints here which prop up constantly. A) H1-B applied by these "outsourcing" Indian companies which treat their employees shabbily (in fact its the US corporations which use and initiate these), so off with their heads. Sure, make H1-B attractive to maybe people who have invested and studied in the MS/PhD grad system. B) But.. now people moan about H1-B Masters and Phd getting "starting" salary lower than what they "think" should be offered to a regular US Citizen. Anyone who has ever interviewed or worked with the top Tech firms (or has managed to clear their interview rounds hahahaha) or have been part of the hiring groups would mostly say that these companies offer very competitive salaries and make NO discrimination at all in terms of talent.
Which side are we debating on or are we moaning the influx of ALL immigrants as unworthy of the job market? All jobs are ours hahahaha Microsoft can't take 10 rounds of interviews anymore since there are only US citizens available for these jobs. We won!