As one owner of the consulting firm explained to me, they'll just use some kind of system, that says "You get paid $100K as a salary but you give back to the company $30K for some kind of service that it provides to you", so in the end they'll end up paying whatever they want.
To stop abuse of H1-B system, they need to limit % of H1-B employees in one firm.
But in general with increasing quality of collaborative tools, that make remote work easier, this problem will keep getting worse. Since companies do not need to hire you when you are abroad, they just need to have contract with your company abroad that will provide them "services" (which is a code word for 100 employees working full time for you in offshore office). Most of the companies already do this and this issue will keep getting worse with increasing quality of collaborative tools and I am not sure what the solution is.