I think in Dubai there's this problem of building underground. I'm not sure but it might be got to do with water of something like that. Because of this towers are either built on top of a podium or else have an ugly multi-storey built behind the tower (as is the case for all the towers along that highway).
I think some towers integrate that pedestral thingy pretty well into the rest of the tower but I'd agree with you there are some which look like plain shite!
Here's what I think's a great design. Even the car park is properly done:
