Backstab requires weapons in a rogue's hand just like a regular strike. In fact, once mid-level, rogues use frontstab as an essential element of their DPS. Rogues should be able to use backstab while mounted. Melee classes get far less value from being mounted than casters and hybrids because they have no mana to refresh; there is no good reason to limit the DPS from a mount as well - especially from hand weapon sources.
Why in Hades name would you be fighting with a rogue from a mount???? I don't see a good reason why melee should dps from a mount. Rogues are not cavalry combatants. How do you manage a mount when both hands have a weapon in them? Kind of hard to reach down from a mount to stab someone in the back as well. I wonder what is your motive for this? No melee fights from a mount. You a massive boxer? Is it for ease of moving everyone on auto follow and you don't want to manually mount and remove mount because software you use isn't designed to do that and you would rather just leave everyone mounted and you have minimal participation as a actual player? I suspect that when you are in a zone where no class can use mounts, you don't have an issue. I main a rogue and only use a mount for fast transportation to my destination. I say no to mounts as well.
No one else can use their specials while mounted, why should rogues? I think that is at the crux of why the Devs have it working this way.
No melee fights from a mount, but traditionally, they were the only ones who fought from a mount. How can casters control a mount and cast with both hands? How is a backstab different than a regular strike for "reaching down"? Sometimes rogues have to molo, and why not use a mount? Otherwise, they are just for casters.
Yeah, I've often wondered why casters are able to move in circles around mobs a group is fighting while casting whatever ever they want... ...oh wait... Mounts are still used primarily for moving from a to b...and placing a horses in your nearest friend. And casters have long since mastered the art of using only one hand...lots of time while looking at their spell book in the old days.
So you are saying that casters use one hand for the book and two hands for the emote. That means they use three hands and control the horse with another. Got it!
I used to kite all the time on a mount. I would use the scrolled back view and strafe on the mount. No delay in reaching max speed that way.
I don't need max speed, I just need to stop fast. There would be too much of a delay between nukes for me.