It's not a waste of 'precious spots' it has to do with thinking on the long-term, they get a way wider room of improvement going to international events knowing more playstyles, maybe even applying them within their game for example. Look at EDG which is from same region as BLG they've improved each international event and right now is a top team in the world. Riot sees it, China is talented.
But you want a unfair competition, benefiting the NA org you root for just because they "invest more in the game" as if this does make any sense