Just because you don't like the art direction doesn't mean its a mistake to take that direction. Its lovely, the minimal textures and polygonal style put more weight on the animations and color palette, which look very nice. With the rise of mobile where things need to be readable at a small size, this style is particularly popular.
AoEO had a charming style to it as well, but this is an RTS, not an MMO-RTS with microtransactions(?) which I think was the bigger issue with AoEO.