Imagine you just graduated from a quality undergrad with high grades and strong recommendations from your professors. Maybe you had an internship or two or spent a summer doing research. Maybe you even have authorship on a published paper as an undergrad. You could be a very strong grad school candidate. Or you could just get a corporate job right out of undergrad.
Lets look at the options.
Option 1: You go to grad school and spend ~6 years working extremely long hours at nearly minimum wage with no benefits.
Option 2: You start at ~100K USD/year with benefits working for Big Tech/Finance/Big Oil/Pharma/Defense/etc. In those ~6 years you likely work fewer hours than a grad student. You have the free time to meet someone and the income to start a family.
Most people will chose Option 2. The two main types of people who chose Option 1 are those who are passionate about learning and advancing human knowledge and those who want a career where a PhD is required.
If instead you're a citizen of "India, China, Korea, Turkey and other foreign countries" (quoted from the article) then the calculus is completely different. Not only do you get to advance human knowledge, but you get to live and work (as a TA or RA) in the US for ~6 years. After graduation you have a good chance of landing a well paying job for a US-based firm or becoming a professor or research scientist.