We used to have a similar restriction! It was called 'the Need button', and if you leveled your job, you could run this content on it and actually get the item!
Furthermore, while this is the intended and main purpose, battle classes using this gear is not the only usage these pieces of gear have. Alliance raids are a very nice way to level up desynth if you have WVR, LTW or ARM and this restriction will hurt crafters who do not have certain battle classes badly. I can't even say it would be better to remove this restriction once the raid is not current-content, because then you're hurting people trying to gear up alts or even their mains after hiatus.