You're absolutely right about that, but where else can you complete a 2 year program that will double your pre-admission salary right after graduation? For some of the international students that get recruited into corporate America afterwards, many are even looking at a 6-fold to 8-fold increase. I agree about everything you just said but there are still no better alternatives to it short of medical or dental. Those have more and higher hoops to jump through, and the day to day for those isn't for everyone either. And of course dental doesn't come with the possibility of immigration. Law has a bigger investment and is also a crapshoot for most people unless your institution is ranked high enough, no different than business. And not sure if there are any immigration options for that path. 5-6 years for a STEM phD is an insane commitment that only certain types of people could look at and think "that's for me". In short, there is no great option and they all have massive tradeoffs that won't work for everyone.
Factor in immigration and MBA, STEM phD, or MD are the only options left. PhD if you don't have enough family financial support and have what it takes. MD if you have what it takes and have enough family financial support or can accept the insane debt. MBA if you have enough family financial support and can only accept a shorter time investment. It's pretty clear that each path is more optimized for a particular type of person with a particular background. So I wouldn't just go ahead and condemn anyone for taking any of these paths really. I've met Chinese people who finished non-top5 ranked business schools who bank near half a million/yr ten years after graduation without needing to invest in their own business or startup. Sure, they were much more competitive than the rest of their class, but the point is this is still very much a viable choice.