I think there's an obvious class conflict when it comes to STEM fields. Wages are high enough that it challenges the corporate class structure that dictates what field should be paid more than other fields.
My wife works in marketing for a company that makes an engineered product and we had a fairly heated discussion about this once. Without thinking about the implications, she actually said that marketing was more important than engineering and marketing should always be paid more. Raising engineering salaries above some ceiling wasn't an option.
Now, my wife isn't a mean spirited snob but I think she genuinely meant this and I think it reflects the class consciousness in corporate thinking.
Strangely I never see this mentioned in articles about H1-Bs and STEM workers. It always seems to devolve into an unresolvable debate involving conflicting macoeconomic labor statistics.
I have seen this also. I think there is an evolution in large companies: even if they start by developing good products, they eventually become so focused on sales and marketing that they forget that the quality of their products is the basis of their business. I was at Digital Equipment Corporation as it went through this transition. By the time the founder, an engineer, was finally forced out, the company was headed downhill, and was soon acquired.
IBM has somehow managed to avoid this problem. While definitely focused on sales, they continue to develop new, competitive products. Whatever their secret is, I wish it was taught in American business schools.