Qatar has a warm climate, but unlike your precious TDU it's not TOO WARM.
Qatar is only a few hours difference with Europe, unlike your precious TDU. You won't feel the jetlag.
Qatar is raced HARD because of the echelons, unlike the TDU which is boring. An uphill sprint on Willunga hill doesn't change that.
In Qatar the big names like Cancellara, Boonen, Cavendish, etc race to win. In the TDU they barely do anything.
Qatar didn't pay MILLIONS for Lance Armstrong to come to their event, TDU did.
Qatar has been the ideal preparation for the spring classics for years now. Much better preparation race than the TDU. Results don't lie.
Without loads of money the Tour Down Under would be nowhere. At least Qatar didn't buy WT status. They let the race grow over the years. Now teams come to them asking for invitations, not the other way around.