It's not about risk, it's about overcoming obstacles. Dealing with US visas is a pain, but it's nowhere near as painful as everything else you need to do to make a startup succeed. If you're going to give up because of a visa obstacle, you're not cut out to be a founder.
I meant that since you have to eventually legalize your stay (say, you have a big exit for the company), how much would being illegal affect everything afterward?
The government wouldn't know you were illegal, that's the point. Is it that hard of a stretch to think of answers to your questions before asking them?
I misinterpreted your answers. My question was under the assumption that the government wouldn't know about you being illegal until you tried to do something related to immigration. At which point the USCIS would know after doing their due diligence. I guess that was a bad assumption to make.
Under that assumption, trying to think of answers isn't any better than a random guess. And I was asking the question for that specific situation, even if it's unlikely, just to know how things could potential be. Furthermore, in the case the government doesn't know about your staying illegally, you would be the same as any random non-citizen trying to immigrate to the US, and it's fairly safe to say that the task is non-trivial (paperwork-wise). In that case, it would still be helpful to know if a founder-but-can't-tell-government would have any advantage at all.
Not every question can be answered by just thinking hard enough, especially those related to laws - that's why there is a whole profession dedicated to it. And it will serve you well to be more careful before going passive-aggressive.
Of the successful founders I know personally, each and every one is incredibly risk averse in anything ancillary to the startup itself.