I don't think it was just stupidity. He didn't have the legs and is clearly not at a good level. Apart from Ganna, take Bernal who is coming back from injury and focusing on the Tour further down the line than the Giro. Egan is in better shape. Not good. This seems like QS bringing him to TA last year in inadequit condition to face the rigors of the competition and getting crushed.
I realize it's January and that it's San Juan, but he can't go to UAE Tour like this and face Pogacar. For a rider of his calibre, who is only racing a few times before the big goal at the Giro, it would be indecorous.
This isn't 2022 TA. He didnt lose 4 minutes. He lost less than 30 seconds to Bernal.
This was a brazen but dumb attack. 10 km out on a 4% climb? The drafting alone doomed the attack. If this were 5-6%, he had a great chance to win. Same if we had the Mortirolo before and this was Aprica