Basically such big names "investing" (helping) surely made a background check and the chance that the investment is good (moon) is somewhat bigger.
But it's a startup after all. And that means that the risk is way above normal.
Even big, established businesses can fail (just remember the social networks from before Facebook). Startups have a way bigger chance for that. And crypto startups...
More than the money the big names bring, it's the reputation.
Bitcoin is not like some company - it needs more than average reputation and credibility, as it aims to replace money.
So the big fish help with that.
You are obviously right (though imho slightly offtopic).
And the reputation works in both ways: the big name may lose some of the reputation if the "investment" fail. That's why a background check is done.
And both - the big fish and the background check - increase the awareness / reputation of the startup (or Bitcoin) and more big fish may come and "take a look".