alt Hacker NewsHow would you prevent people from getting an H1-B visa for a job just for the sake of moving to a different job in a sector that doesn't need a lot of workers? And if they are going to start a business, they could start a business in tech that is actually successful, and then fill a few extra positions with friends/family/contacts/people willing to pay, and then those people could move on to other jobs for which they are more suited.
Fact is, immigration systems in all of the richest countries are already bursting with abuse from certain countries with very ingenious schemes and you gotta have some ways to protect it unless you want a free-for-all.
I would encourage you to actually read up about the hoops that people with H-1Bs have to jump through just to stay in the country. It is a demeaning and abusive process, and not usually one that people engage in frivolously.
Additionally, you can already today legally switch jobs as an H-1B, but it is a process that gives undue amounts of power to the employer, which makes switching difficult. Finally, regarding switching fields, it's not that easy. You have to show that your new field is related to your degree and experience.
So please, instead of making up imaginary bogeymen, learn more about the immigration system.