As always, it's marketing.
With the identifying markings on the bottom, it wears off when you set the camera down with the hood on -- as mine are doing. Eventually, they wear away and you don't know which hood is which -- so you have to buy a new one!
A reach, I know. Who the hell knows really.
Yay, that is a good point. Don't want those markings to wore off. They make up 90% of the hood price (if it did not come with lens)
Bodies: Canon 6D, T2i gripped, EOS 5, EOS 100, EOS M
Lenses:EF 24-105 F4L, EF 70-200 F4L, EF 70-200 F2.8L mkII, EF 100 F2.8L, EF 50 F1.8, EF-S 18-55mm, EF 28-80 USM, EF-M 22,M mount adapter
Other : 540EZ, 320EX, 430EX II, Yongnuo triggers & strobist stuff