Comment by anonthrownaway

I don't buy that. I would guess there are plenty of "joe/jane users" that are tab hoarding using horizontal tabs because they don't know better. Since Sidebery already built it, it would be reasonably easy for mozilla to implement a vertical tabs solution that matches its functionality and would seem innovative as hell to joe/jane. Instead, they decide to copy Apple's bad UI/UX.

Setting my browser up the way I did was a serious PITA and it didn't have to be.