You see, bandwagon usually isn’t about objective value, but the perceived one.
Sure the barb wagon started because of the broken crit multiplier (actually OP), but even after that was fixed people still go for Barb.
For the people who can view things objectively, it’s because Barb’s buffs work to increase DPS as percentage (crit) and since many of them work for any weapon it’s a great supplement to whatever other class they want.
For the rest, videos of Barb doing SOMETHING (like Steparu’s Barb->Corsair playing around with Toyhammer’s proc) make them think it’s OP and jump on the wagon. (similar to that max lvl, geared Hoplite killing a lv 130~ boss in under 20s)