Well, I a heatran comes out, just switch. Heatran is one of the only pokemon that can block a scizor's sweep. You do have dragonite or jellicent to sponge a fire hit and chase heatran out. If you play smart, you can make your opponent keep Heatran back away from scizor, because you could be using it to lure in a heatran so Dnite can set up....
Besides, knowing that any sensible opponent will switch their scizor out, they use that free turn to set up rocks. If there are already rocks up, switch. If there aren't, most of the time it's safe to uturn out.
But yeah, scizor's sheer power overrules its few negative aspects. In fact, it's Base speed exceeds magnezone, so you could tailor its EV's to outspeed magnezones and KO them with superpower. It all really depends on what your team needs most.
Blaziken, NOOO!!! T_T
*goes off to weep in corner*
O HAI THAR, I'M AN UPTIGHT SMOGONITE AND IMMA BAN EVERYTHING THAT ANYONE FINDS SOMEWHAT ANNOYING. NEXT STOP, REUNICLUS, CONTRARY, AND VOLCARONA. U MAD, POKEFANS?
...but, of course, we're never banning E-Drill. Anything that counters sand must be thrown out at all costs.
If this type of rabid ban-happiness continues, we'll need a tier between OU and Ubers. It'd basically consist of normal pokemon that are banned but not legendaries.