I don't think it's fair to write-off food in Spain based on Portaventura! Culinary and hospitality culture in Spain can be among some of the best in Europe. Food at the park hasn't always been as bad as it is these days. Nor have the operations, although they've always been a bit sluggish.
Similar to Merlin in the UK, I think market dominance is at least partially to blame for the slack elements that spoil what was once an outstanding park. It was a favourite of mine a decade ago, but it hasn't at all kept up with Europa Park, Phantasialand or Efteling.
Also, Baco is indeed, absolutely dreadful.