They've tried in the past. They just never could get it together to make anything good. They put out some truly awful bass amps in the past. Naturally they bombed.
Leave them to make guitar amps. Some of them are good.
Yes... I never owned, but I played through a Vox Beatle a buddy had - - what a horrid amp. Mud-Fart, nothing but Mud-Farts.
Like the man said: They make nice guitar amps (the AC-30 is great) but bass gear? Nope.