Congress explicitly intended for the H-1B to be a stepping stone to an employment-based immigrant visa. Why? Two reasons:

(A) Prior to 1990, the processing times for employment-based immigrant visas were in the order of a few years. Practically speaking, no employer ever sponsored someone for an EB green card if they weren't already working for them at an office abroad. Congress wanted to provide a practical pathway for skilled immigration. The quote "non-immigrant" H, L, O, are explicitly intended to be stepping stones to permanent residence. Look up the Congressional record on this matter (ie debates on the 1990 Act) . There were also some articles from the Cato Institute elucidating this, but I don't remember their names.

(B) The original 1990 bill explicitly exempted H, L, O visa holders from having "non-immigrant" intent. The fact that folks on H, L, O are "non-immigrants" is an accident of how the Immigration and Nationality (INA) is structured. If you're not required to maintain "non-immigrant intent", and are explicitly allowed to call the United States your home by the law (specifically, the INA) you are in no sense a "non-immigrant". The later AC21 bill went further and made people waiting with approved employment-based green card applications, exempt from the 6-year H-1B limit.

Finally, it is insulting and degrading to be called a "non-immigrant" when you have lived for over 10 years in the U.S., by people who have no understanding how the system works, like yourself. I'm trying to be less triggered by comments like yours on HN, but it's difficult. I have to say that based on your commenting history here, I've noticed a very clear pattern of xenophobia, so even if you did understand how horrid the US system is, you'd still likely enjoy insulting people who've lived here for 15 or 20 years, by calling them "non-immigrants". But that's your prerogative/freedom. TBH, despite being a lawyer, rayiner, you have no knowledge of the legislative history of the INA, and shoot out falsehoods from your mouth, with an air of authority. I don't know what causes you (or caused you) to be so incredibly hateful towards immigrants, and I don't really care why either. But please don't turn HN into such a hostile place for non-citizens living and working in the US. I remember reading your comment from a month or so ago, where you called Canada's immigration policy "ruthless". That's a degrading term (towards Canada). I think their skilled immigration policy is the best in the world. Canada is a country that values skilled immigrants, and treats them with respect and dignity. I deeply wish the US had an immigration system similar to Canada's. But it doesn't. Canada is doing something good. But you chose to insult them for it. Canada's immigration system is the best in the world, and it actually allows a skilled person to get permanent residence quickly, and doesn't force you to spend a 10+ years on visas with limited rights, freedoms, etc.
So please don't insult Canada. And ironically, while I can make $200k+ in the US, I am tempted by the freedom that Canada offers, despite lower pay there. It's unfortunately all-too-common for anti-immigrant folk on HN to paint all people on work visas (H, L, O, etc) as working for bad employers, or being thoroughly underpaid -- but this is rooted entirely in ignorance (or in willful dishonesty). My base salary is $140k+ which is an "OES Level 4 Wage", and I've made over $200k with bonuses in the past. Then there's folks like throwaway082729 who make $650k/yr: https://news.ycombinator.com/item?id=20473537 When xenophobic people on HN are confronted by facts like this, it causes them cognitive dissonance, and throws into muddy water the foundation for their hatred for immigrants. And what happens? They simply downvote. They can't accept the fact that everything they've believed about skilled immigrants (e.g. being low-paid) is utterly false. Please don't be like that. Please try to be a better person.