Diego Falcinelli had the minnows 2-0 ahead at halftime. Inter fought back after the break with Danilo D'Ambrosio, but Eder's chance of equalising came off the woodwork.
“Clearly we didn't have the right approach," Pioli told Mediaset Premium. “We made too many mistakes, it was a game that should've seen us go into it differently and we ruined it at the start.
“We tried to get back into it, but we made life too complicated for ourselves. Everyone is to blame today, as we had players with experience and quality who didn't give Crotone the right amount of consideration.
“Fortunately we have the derby on Saturday, as there we must prove that we're not the team you saw today. I think it is a psychological issue, because otherwise some of these errors are inexplicable.
“We lost an important home game to Sampdoria and therefore should've been even more humble and focused today, not less. In the first 20 minutes, we left the doors wide open for Crotone to walk through.
“It's a painful defeat, we need to react straight away and what better opportunity than the derby? In today's football consistency is the key to everything and we had that for four or five months, but the last two setbacks were unexpected.
“We've got what it takes to prove we're working in the right direction. If that doesn't happen, then it's only right that we are criticised."