As fazalwahab rightly said, sales numbers might define a successful car but not necessarily a "good" car, that's largely subjective.
I know kia's no vanguard of quality, but that's a pretty poor argument. Surely you're aware of how much they've improved over the years? It's not the 90s anymore, let's move on.
P. S. not a kia fanboy, just happy to see something without a honda or toyota badge on our roads.