Most of the best players are South American, and as they are Spanish/Portuguese speaking can acclimate faster/easier in Spain versus England, no to mention weather is usually nicer (milder winters, etc). They are much less Anglo-centric than we Americans (we have history with England, common language, therefore feel closer to them) in fact in Argentina there is some very real antagonism towards England (Malvinas/Falkland Islands war in the 1980s). They pride themselves on their Spanish/Italian heritage so are much more eager to go to those locations for themselves and if they have a family. Money only accounts for so much.