It's true that a solo Barbarian with some well spent 250-500k at the Auction House can destroy everything in Act 1 Inferno ( %VIT, Resistances and a decent 800-950k DPS 2-Handler). OP is right, we're talking about a SOLO barb. In a 3/4-player party, it's HARD.
However, since you're the most gear hungry class, your gear needs to grow BIGGER and FASTER in quality than in the other classes as you go to Act III & IV.
People who say otherwise are narrow-minded.
true, a skilled barb also solos a1-a4 inferno... kripp already steamroll 2-3 elite at once while chasing goblins!