Spaniards attitudes can be quite different from the American ones, Americans just pay for everything for convenience, in Spain you probably need to match the price of the IPTV to steal their customers.
Apparently IPTV costs 20 to 60 Euros per year, the legal option is over 100 euros per month.
To match the IPTV they need 20x price reduction. This would mean that they need sign in 20x more Spaniards to break even with the current situation. Are there 20x more Spaniards pirating the LaLiga than paying? Even in Spain I don’t think so.