There are two reasons:
REASON
ONE
Footballers prefer Real Madrid simply because it is offering
highest salary.
Google for the 50p tax rule imposed by the Labour Party (Gordon
Brown) and you will understand why.
During contract negotiations, Class A footballers demand wages
that are post-tax. This means English
clubs will find it alot tougher to match or exceed the wages that
are offered by Spanish Clubs.
REASON
TWO
Footballers prefer Madrid because they believe Real Madrid will
never go bust (like Leeds FC).
The legal structure of Spain is that each province is fairly
autonomous in its insolvency laws. For deep seated clubs like
Barcelona (Catalonia) and Real Madrid (Madrid), the legal autonomy
means that well connected Presidents are in a position to hold off
insolvency by leveraging on the interests of creditors (being
ironically also the same people as the investors in the club) - no
matter how indebted the club becomes.
There are arguments against the viability of the "high debt -
high revenue" model of business model for football club (Google for
these yourself), but for Madrid this appears to be working.
Although Man Utd under the Glaziers is also operating on the
"high debt - high revenue" model, Man Utd cannot take on as much
debt as Real Madrid, because (i) the legal regime for insolvency in
UK is less forgiving; and (ii) Man Utd is a publicly listed club
bound by need to show profit to shareholders.
