Because of language and the like, and culture, which is quite funny, because at that time Latin Americans probably felt a lot more favourable towards many other European countries or countries other than Spain. There was no huge love between Latin Americans and the Spaniards, at least in the minds of many Latin Americans.
It also came at a time when Spain was opening up. Remember, this is the late 1980s or early 1990s, when Latin America was going through their whole privatization and their neo-liberal opening. So the confluence of a number of factors, in the Spaniards' mind, said, this is our time to do it.