There is no single answer for this but I believe it also helps promote better systems(political/economical). It's obvious that a gifted person without support from the environment can achieve very little. Think of what Steve Jobs would have achieved if he was to be born and raised in Syria. Not much I would say.

Therefore I believe it's right for people to pull pride from someone's else work through association. You (would) have no SpaceX without the US capitalist system.

When NASA or SpaceX does something, it's an accomplishment of the very people working there, then of the people who supported them and not least of all the humanity. It'a like winning a war. It's not only the people that fight in the front lines that matter. It's a whole system.