It's not really the Bonus Action use that's a problem as you are getting damage out of it; the real issue is 5e requires Two Weapon Fighting to add your ability modifier to the damage and that feels bad in a CRPG. They could add the effect of Two Weapon Fighting to Dual Wielder feat and then come up with something else for Fighters and Rangers to get instead of TWF. That might annoy some of the DnD hardcore, but honestly Fighter and Ranger are two of the weaker options right now outside of GWM...
