I use a controller for cross hotbar and I also don't think I understand it enough to know if i want a second one. I don't know how that's supposed to work like at all, even after reading it. It sounds like a logistical nightmare. L1 already has a use and R1 already has a use, so unless they're gonna go R2+R1 and L2+L1 i am at a loss. However, I think I would like such a thing to put my pretty-much-never-use-but-maybe-i-will-use-this-eventually bar.
Like giving Shadowbind a place to live instead of shacking up on my never used hotbar.
Also Re: Minions/mounts/titles that people don't care about - To the best of my knowledge, WoW mounts and gear are something of a status symbol. There was even a kotaku article about some skin earned on LoL that carried prestige with it because of its hard-to-get nature. People care(d?) about Savage Second titles for a while. What makes you think that a blanket statement of "a lot of people don't care about titles, minions, glamour" carries any weight? That's also why I said you can give out multiple rewards because some people really love housing items, some people really love minions, some people really love titles and some people really love glamour (everyone should). If you want to have a version of have and have nots, you can't just restrict it to gear because gear will fade at some time. Be it now or then, gear will eventually turn into seals or be desynthed. Mounts and Minions won't be.
If Mounts/Minions/Etc don't do it, then maybe they can introduce something else that could be more permanent that you can show off for completing such a feat - something that will add lasting prestige beyond the temporary fix of gear? You can still give out hefty gear, sure, but other rewards I think would be a nice way to go about it. People may bitch and moan over it, which is why I highly doubt this would ever happen, but in my mind that's the absolute best way to cater to the hardcore and cater to the casual. Give people something tangible to work towards that isn't just badass +30 ilevel gear.
Or make the best and highest ilevel savage gear all bikinis to force people to want to get good. Maybe that's the best solution. Hmm.