What could be attractive in a desert? It is not the Sahara, but the possibility that there isn't any interesting until the GUT scale. On the Wikipedia, I've read:

"The attraction of a desert is that, in such a scenario, measurements
  of TeV scale physics at the near-future colliders LHC and ILC will
  allow extrapolation all the way up to the GUT scale."

Consider we have the negative information, i.e. somehow we would know, or we could suspect with a quite high propability, that there is really nothing until the GUT scale. Could be this negative information also useful? If yes, how?
 A: This is very speculative stuff, but here's how I understand this. The `desert' means there are no phase transitions. The whole thing about the TeV scale is that we know there is a phase transition there. The theory above this phase transition is different from the one below the phase transition. Currently we have a potential theory that is proposed just above the TeV phase transition, namely the Standard Model, but it has some theoretical problems. That is why we are investigating the physics at the TeV phase transition so that we can see if we can improve the Standard Model. If we can somehow improve the Standard Model so that these theoretical problems disappear then we would have a theory that applies all the way up to the next phase transition. If it is true that there is a desert all the way to the GUT scale, then the next phase transition would be then one at the GUT scale and then we can start to investigate the GUT scale physics in terms of this new theory. Hence, the benefit of a desert.
