Another reason why it isn't popular is because it's a kids anime. (If you don't believe me, it's on the kids selection on Netflix)
The anime that most anime fans watch are usually mature and more for older teens.
A kids anime isn't really a weeb/okatu's anime, so they are usually ignored. (Unless it's a long running anime, such as Pokemon, then it's remembered, but other then that, they're left in the closet forgotten about.)