Well the meterless combos are kind of a huge deal. ~30% with Warlock compared to ~15% with BS is considerable to say the least.
Also you talk about both of them needing meter to get any high damage. Bone Shaper and high damage? Don't make me cry
His 1-bar BnB does as much as your meterless BnB. Anyway this is isn't related to meter-dependency so back to the point...
Without meter BS loses his Hell Sparks which is a big chunk of his neutral/midscreen gameplay. I think Warlock can handle himself better without meter in the neutral.