It's not dumb, if they don't like the game because a prominent feature of the older games isn't in, they have every right to express their distaste. If the designs aren't amazing enough to change their mind on the quality of the game, that's just how it is (it's completely subjective). Personally, I haven't seen anything that appeals to me, regardless of the National Dex controversy or not. Whether you love the game or hate the game, I think it's important to at the very least respect the opinions of those who disagree. Pokemon appeals to different people for different reasons--some like the story, or the battling and they don't care about the controversy, whereas others play Pokemon as collectors, and it's not what they have come to expect. The only problem I see would be the trolls who just complain, regardless of their genuine thoughts.
As for me, I've resigned myself not to express my feelings on the game, because of the backlash of the backlash (and the extremely toxic nature of the discussion in general), and also it's not my series to get too worked up about, as I fell off of Pokemon before the DS era. Also, regardless of my feelings, my bf said he's going to buy me Sword and make me play it.