If the opinion of the gulf state king about the Rafale is of little relevance, the context of his sentense, however, is quite interesting :
[...]"King Hamad asked General Petraeus for his help in encouraging US aircraft manufacturers to participate in the inaugural Bahrain Air Show, scheduled for January 2010,"
"He said that France was pushing the Rafale and would be there in force although he agreed with Petraeus that the French fighter was yesterday's technology"[...]
The very interesting outcome of this cable is not what King Hamad said about the Rafale (what does he know about military aerospace anyway ?) but the fact that he is actually using the French plane as a mean of pressure on the US General Petraeus to get more US aircrafts at his airshow.
So the question is : why King Hamad has chosen the Rafale to pressure US authorities rather than another European or Russian fighter jets ?
Well, simply because the Rafale technology is the only one capable of annoying a US General ... :)
Also read : Bharain officially denies wikileaks cable on Rafale