It sounds to me like this is more of a lag issue for you than anything else. Scorpion is by far one of the easiest people to fight against after you've discovered how to do it. Seems like you're allowing yourself to be zoned and if that's the case you'll never be able to beat anyone doing that until you find a way around that. The best way to fight him is by getting in close on him. The leg takedown is easy enough to deal with as long as you block low. Both spear and teleport moves are extremely telegraphed and easy as hell to see coming. I definitely disagree that his spear is too fast, it's perfectly fine the way it is.
I can see why you're having a tough time closing the gap since a good Scorpion zoner can make it a pain in the ass to do. If you were to choose someone that also has a teleport, it's quite easy to accomplish. However, it's not necessary to do that, as he can be very easily beaten without that tactic.
The more you play against people choosing Scorpion, the better you'll get at finding his many weaknesses. Just remember that the key to fighting him is to stay in fairly close. Good luck to you and I hope that you'll be whooping those spammers in no time, lol.
On a side note...............I have to agree with many other people on this board lately. Everyone, please stop with all of the nerf posts. There are no characters that are OP. This game is extremely balanced the way it is. Yes, there are several glitches that need to be addressed, but other than that it's perfect. So just keep practicing and enjoy the game.