The argument the article makes is, literally, "Your idea probably sucks, and it doesn't matter because your business will probably turn out to be something comp

The argument the article makes is, literally, "Your idea probably sucks, and it doesn't matter because your business will probably turn out to be something completely different." You are arguing that "there are millions of ideas that keep sucking even when modified." He's saying, yes, your INITIAL idea may suck, but any successful businesses created with it would likely not be the same idea, so it doesn't really matter to wait until getting a perfect idea, and here are some examples. So don't be afraid to start! If you succeed, it won't be with that idea, very likely! And it may take years of time! And it won't necessarily be the very next iteration of the idea that changes everything. The author is not saying you will succeed for sure, or that changing one's idea is the most important factor (both are essential to your argument, but it's not what he's saying, on the other hand.)