That cuts down on half of the utility brought by the expanded bars. You lose so much real estate by limiting yourself like that. On my DPS Jobs (DRG and MCH) I have buff skills in the same spot (Triangle on both R2>L2 and L2>R2 - Heavy Thrust / Hot Shot) and a few other skills get the double-dip treatment (like I have Leg Sweep on both sides, and Gauss Barrel in the same spot - down on dpad) but I think it's strictly beneficial to have the two sides as being unique and then getting used to having 8 different skills on either side.

Like, for Scholar, my R2 is all my healing stuff (Physick, Adlo, Lustrate, Embrace, Emergency/Deployment Tactics, Aetherflow) and then R2>L2 brings up all my raid heals (Succor, Indom, Sacred Soil, etc). And then L2 is all my DPS stuff (dots, Broil, Energy Drain, Cleric, B2) while L2>R2 brings up extra DPS skills (Shadow Flare, Miasma II, Bane, etc). Virus is on the DPS expanded (since I'll generally be targeting an enemy when I'm on L2) while Eye for an Eye is on the healing extended (since more likely to be on a party member on the healing side).

It works for me, doesn't work for everyone. I just think it makes sense to set it up that way. I also know someone who plays on controller and has Physick macros for every person in the party <2>, <3>, etc to <8> not including <me> since it's easy to de-target and cast. He has Physick+Embrace mapped to the tank ones.