If you're binding job appropriate gear I don't see a problem. Ex: Bards binding Spinel (Dex) sets. I bound full accessory sets while doing my daily roulette's and never once had to buy materia for my Novus. You're not hurting the party any more than a fresh 50 would. Heck, I'm still il80+ while binding full spinel sets. People just like to complain about anything.