If Sin Cara is such a great merchandise seller why is the character jobbed so much?

I'm sure many of you here have heard about the whole Sin Cara character and the reason why they wanted to keep him on the roster which Hunico took over the role as we know, apparently he's such a great merchandise seller as well as them including him in things such as The Scooby Doo movie for example, they obviously wanted to keep this character going for various reasons, though what baffles me is how come they always have the character jobbing to other talent when he's obviously a fan favourite if he's selling merchandise well, surely these fans want to see him win now and again.

I realise with Mistico it was a case of injury's and botches, however Hunico is an absolutely solid wrestler, yet the character is still booked the same way, so why do you feel that even though the Sin Cara character is apparently a good seller in the merchandise department, why do you feel his character is booked as though it's a Heath Slater, Jinder Mahal kinda thing? (I.E. a non merch seller basically).

What are your thoughts in regards to this?​