Why shouldn't a R1 be allowed to wear R50 gear? In the optimal system they're not gaining any benefit from it, in fact they're hurting themselves for not wearing gear their rank. Does it make you feel less special? Sorry to hear we can't all be special R50 snowflakes. I know you want to lord your great "achievements" of gear over people but there's no other reason to want rank requirements. You can have goals with optimal, you can have class uniqueness with optimal, you can feel special with optimal. It all hinges upon the user being smart enough to actually wear the gear they're supposed to, apparently a lot of people are too stupid to do that.
Optimal works fine, the penalties just need to be shown more clearly. Obviously people need it spelled out for them in bright bold letters otherwise they won't see it. Maybe they should have a prompt pop up that says "Are you sure you want to equip this? Its optimal rank is above yours, you won't receive the full benefits from this piece of equipment."
Optimal would be great if they just made the penalties more visible. Optimal can exist alongside rank/class required gear.
http://www.vgcats.com/comics/?strip_id=214
^ related, also hilarious.