Basque country is, again, rich because it has an special tax treatment and could be considered a tax heaven to some extent.
I'd say its a well developed region comparable to Northern Italy. Both were badly hit by the Euro. Had they kept their own currencies, they'd be closer to Sweden or Southern Germany.
Spaniards tends to have this idea that Spain is a shithole when it’s really one of the best countries in the world.
Its looting of the gold and silver from S. America apparently didn't help.
You may think it is sad, they may just think it is the way it should be done and that's it. I don't think you can judge the coop concept based on the impression you got from the city. Its inhabitants may on average feel happier than those where you live.
But lots of employees live and work in much nicer spots like the San Sebastián area.
Many engineering and hardware companies all around the Basque Country are owned by Mondragón.