Well for one, Klefki can't learn Swords Dance. It's also far less tanky than Tinkaton, and while it does have more attack, it eats shit in nearly every single other category compared to Tink. If you pit the two against each other, Tinkaton would have spiffy new keychain on her hammer.
So this is a pretty retarded comparison. Then again, people needed to compare Mawile to Tink, despite the former having shit tier stats compared to Tinkaton, so it's safe to say that everyone's only looking at ATK for some reason.