I know popular doesn't necessarily mean better (fast food?). But, sometimes, it does.
If you know for sure that the people at WotC thought a format like Pillars would have been a better match for what they envision a D&D game to be, but decided to go with Larian anyway, then sure, you can say they sold out. But it just as easily can be the case that they saw how what Larian did resonates so well with what D&D is and thought it was a win win for them (better product, better sales).
