I think it boils down to Bards having so many abilities that can be used off of the Global Cool Down. It's kind of strange to me that Archer has so many but Pugilist's dodge condition ability can't even be used off the GCD. In certain situations you can slam in 3 abilities in one GCD: If you're in range to use Repelling Shot and the target is at less than 20% health you can use Heavy Shot (which starts the GCD), use Bloodletter, then use Misery's End, then use Repelling Shot. It's constant damage with on demand burst and even bigger conditional burst. Plus, Bards aren't subject to DPS loss due to having to dodge the plethora of melee AoE and conal abilities that melee has to. You might not hit as hard as melee can when they can hit but you'll always be hitting for a modest amount.