That is because 96.9% of those Sorc’s and Pally’s are bots. As long as Blizz can control the boting that should change once D2:R rolls out . If you do not know how to run basically any class in hell you are either unwilling, incapable, or do not have decent gear yet.
I played D2 for 15+ year’s exclusively and of that 8+ on HC never once using MH or a bot .After a certain point it only comes down to gear and desire. I have run hell effectively with every class with very little trouble beyond immunes and they can be problem for any class no matter the build.