Two reasons -> it's not an OEM clutch. It's an aftermarket one - could be better, could be worse, probably just as good, but different materials so it grips a bit different. And, it's like old tires vs new tires - you get used to the old tires being a bit "greasy" and then you put new tires on and it's like magic, but in reality you're just back to where you were when the old tires were new.
Still feels good tho.
Ray