Any idea why this shift shaft seal would be leaking?

My experience this time was since the seal was almost out anyway it was easy to get out with just a pic. Didn't need to use the special tool. Which came from the manufacturer needing to be clearanced to fit over the shaft anyway. Went ahead and did that just in case. Like I said seal came out easy. Had to get the new one started with the socket, wasn't quite enough room to get my giant ballsey C-clamp (8 inch) between the transmission and floor tunnel. Finished seating the seal with the installation tool. All In all not easy but not too bad. Just takes a little time.