The problem isn't straight up payment in exchange for being "accepted" into YC. The same way people don't straight up pay employers for H1B visas.
The problem is that it still allows private individuals to profit by being gatekeepers to the country. Extracting unfavorable financing deals that wouldn't be tenable if the investor didn't also hold the founders' residency permits, extracting corporate governance concessions for the same reasons. The list goes on.
We've seen widespread abuse of the H1B visa when it comes to turning labor into near-indentured servitude, particularly around the green card process. There's no reason to believe that YC, or any of the high-profile players in the Silicon Valley Funding Party are above it.
> "1) Would it be so terrible to have people who have enough money to afford such a bribe be in the US contributing to the economy?"
Yes. There is an investment track immigration option for people who simply want to buy their way into the country - this money goes to fund all manners of things, instead of into private pockets of a hypothetically corrupt YC.
http://www.uscis.gov/green-card/green-card-through-job/green...
> "2) Do you really think YC would stake their reputation on such an abuse?"
Yes. Absolute power corrupts absolutely. If you give anyone the power to completely upend someone else's life at a whim, abuses will occur. Incentives are incredibly strong, and the slope is incredibly slippery. It will start with a gentle tilting of negotiations in favor of investors, and over years evolve into progressively more aggressive concessions.
At no point will anyone feel they are doing something overtly evil, just like how holding promotions back and lowering raises is just a matter of course when someone is in the midst of a green card application right now. It will all happen slowly enough that it won't feel like "abuse", it'll feel like "just the way things are".
> "3) O1A visas are often given to artists, actors and athletes. Do you think that there isn't at least a few theater and movie production houses (usually underfunded and desperate for cash) that are accepting the payments to list a rich foreigner as an "actor" in their show?""
Are we really making this argument? This boils down to "there is abuse happening elsewhere so we'll tolerate abuse here". Abuse of a system is abuse of a system - that it's happening elsewhere (possibly happening elsewhere I might add) doesn't justify it in our own back yard.
Letting private individuals gate-keep the country's citizenship/residency is a terrible, awful, stupid idea. It is a good idea only when predicated upon the assumption that the leaders of our industry are incorruptible.
Look at the Bay Area. Really look at the Bay Area. Is there any convincing evidence of the tech industry's incorruptibility?