The problem is, I'm not sure that the Euskaltel guys really do disrespect the Classics. They do their best at them, it's just that, frankly, their best at those kind of races isn't good enough, but they have to be there because of the WT licence, and with sponsorships contingent on the WT licence they needed to get one.
Sky are the top team in the world and it's very surprising that they can't cobble together 8 riders here. Even if some of them are neo-pros and the weakest parts of their squad. Still, we've seen more ridiculous things in the recent past, have we not? Like Radioshack, a team with a 25-man roster, claiming they couldn't send a squad to the Giro as they were focusing on California.
edit: also, with Catalunya now looking like it might go belly up, and the economic situation killing off almost all of the stage races in Spain, the organisers are probably quite upset as they got bailed out by Sabadell Guipuzcoano last year on a two-year deal if I remember correctly, so would be hoping for a good lineup this year in order to cement their sales proposition for prospective new sponsors. But with no Valverde, no Rodríguez and also some other high profile withdrawals like Mollema, they're probably getting a bit frustrated and so the announcement that Sky are only sending six riders has drawn a bit of a reaction.