David Spade -- Sick Of People Trashing JPP ... Have Some Empathy!!!

David Spade says he feels TERRIBLE for Jason Pierre-Paul -- claiming the NY Giants star got NO LOVE from people after he blew up his hand ... and that sucks.

"I feel bad because when he had his fingers blown off no one said they felt bad for him," Spade says.

"Everyone just said what an idiot, what a loser, he deserves it ... he was just trying to light firecrackers for kids or something."

"He blew his hand off ... I was the only one going, I feel horrible for this guy ... someone should have some empathy for him!"