actually I think they're right, rpg's havwe always used a pretty fucked up perspective in my opinion, but if circles should look like ovals, then the squares of the ground should look liks rectangles, which isn't the case.
As far as I know,in most 2d rpg's (at least the old ones) the perspective shows horizontal stuff AND vertical stuff without distorting them, wich is pretty flawed as a concept, but we're used to it by now.... In some cases like the circle of stones around the trees, the ovals look okay, but in larger stuff, like those magic circles, which have under them a grid made bu square pieces. It would look odd to have an oval against a perfect square, it would make the circles look distorted...