The thing about basketball is that it is typically not a sport where it's a primary interest.

Go to places where you find good Basketball players. Germany, former Yugoslavian countries, Spain, Argentina... All those places are primarily Football countries.

You will find a few people interested in the sport, some youngster might be playing it for fun, but still very much behind football.

It's just not comparable.

Aren’t the ideal bodies pretty different for basketball and soccer? Are 6’6” guys a good size for soccer? How about taller? I’m sure European basketball players grow up playing soccer but at some point they end up playing to their strengths.

That's... very American of it, still? The idea of a single sport in a country is weird and silly from a US point of view. I'm more interested in hockey, why would anyone think that would make me not a fan of basketall or football or baseball?

But... so? I thought we were talking about if these sports had "nearly no popularity"? Not if they were displacing soccer entirely. "Nearly no popularity" is pretty obviously false based on eyeballs and sales, even if soccer is more popular... And there's a lot more countries and people in the world than just Europe. (But also very American of you to ignore them ;) .) How much would it even matter to the NBA if China is or isn't primarily a basketball country, or just a country with hundreds of millions of fans that also have another sport above it in their personal rankings, if they're making money either way?

EDIT: and of course the name "soccer" originated in England because there were multiple foot-related games and so people made a more specific name. So maybe the weird countries are the ones that lost a fun multi-sport ecosystem and ended up a monoculture...