"If you build it (so it's good), they will come" is a brag of popular and successful people. It's saying "people came to my thing because it was good, and didn't go to my rival's thing because it was bad". It's saying whatever the status quo is, that's how things should be. It's saying whatever is popular, it's popular because it's good.
Notice the passivity, you build it, they come automatically. You don't make them come, it just happens by itself. (And if it doesn't? Way more things are built than gain audiences. Well, then you didn't deserve success. Because the meaning here is you build it, you sit around passively to be judged, and then whoever has success deserves it and is good.)
Saying, "Don't worry about getting the word out, just make it really good and success will follow" is the same message. It's defending the status quo, and saying everyone's place in the world is where they deserve to be. It's the elite asserting the rationality of the world that made them the elite.
People also mix up making something people want and making something good. Lots of people have bad preferences. Pleasing people makes it easier to get attention/customers/fans/etc, but it's different than making something good. Again the issue is a claim about how great and rational the status quo is. There are lots of people who devote their lives to pleasing others, and want that to have been good.
The idea that quality ensures success is wrong. And it flatters successful people.