Both Machamp and Heracross are rated 9, Scizor is 8. Only 7 gen 2 pokemon are ranked higher. Scizor might be good against Blissey and Snorlax, but he is double weak to fire and doesn't have great stamina. Compare him to Alakazam, which has an 8.5 rating...both have great attack ratings, and both have similar stamina/defense, with the slight edge going to Scizor. But Alakazam doesn't have that double weakness.
Scizor
Why is Scizor only rated 8? It resists all Blisseys moves and most of Snorlaxes. I realize Machamp and Heracross are better but isnt Scizor among the best after that.
Answers
but doens't shine in anything.
I think with Fury Cutter/X-Scissor he shines against Exeggutor. He resists all of Exeggutor's attacks (in fact, he double resists the grass attacks) and is double super effective in attacking against Exgeggutor as well. He is also almost as good against Espeon (except he is "only" super effective against Espeon).
"I realize Machamp and Heracross are better but isnt Scizor among the best after that."
Tyranitar resists almost all moves and has tremendously better stats, leading to faster win and better health. Vaporeon doesn't resist, but has better base stats, leading to better health and similar win time. Exeguttor only resists Psychic, but has better base stats, leading to tremendously faster wins and better health. I could go on, but the point is there are quite a few attackers with better base stats, which are often combined with better moves. This relates to why Scizor is not higher than 8.