The Giallorossi had been unbeaten in 20 rounds, winning 16 of them, but at Fiorentina and Toro have now lost two of the last three games.
“I'd say we got too stretched out and left the defence exposed rather than blame the defence for individual errors," Spalletti told Sky Sport Italia.
“We lack determination and waste opportunities. Today this happened at the start of the match and we still had time to turn it around.
“Torino did well to take their chances. If we analyse the team overall, we have too many ups and downs. When the first difficulties arise, our heads drop, we lose enthusiasm and struggle.
“We seem to expect our quality to just emerge by itself, but without the effort and mentality to bring that out. There is a certain arrogance in that, in waiting for things to just happen by themselves.
“Unfortunately we have a long history of not maintaining the same level of effort and concentration for 90 minutes. We have these ups and downs and the Coach is the first person to blame if we don't find that consistency."