it's a matter of budget and political will. Spain simply cannot afford all these train lines, and the system fails. But hey, we have high speed train between Villacojón del Caudillo and Cagalera de la Reina, because they happen to be aligned to the center of the country (Madrit). These railways make no economical sense, they were built for political reasons, to support a "radial" concept of the country that does not really exist yet.

Meanwhile no high speed rail between València and Barcelona, because that would somehow erode the power of the central elites.