The Spanish people were extremely happy with the Muslim rule for more than the first six centuries. When Muslims became decadent with a luxurious life style and mutual dissent, bad governance naturally followed which incited displeasure among the masses, native Spanish and Muslims both. That resulted in massive discontent and rebellious attitudes marking the decline of the glorious Muslim empire until the hatred of people drove them out in 1492. Ferdinand and Isabella had exploited the situation to a great advantage.
Anecdote: The last emperor was crying in 1492 when his mother said, "There is no use of crying like children when you could not defend your empire like a brave soldier."