Usually Nidoking is used as a scarfer, so it only gets the Sheer Force boost. The very rare LO set that acts as a wallbreaker seriously lacks in Speed.
A M-Nidoking that keeps Sheer Force essentially has a pre-built Life Orb inside it, so the damage output is more or less the same.
By adding some more bulk or enough Spe to outspeed key threats Nidoking instantly becomes a pokemon that can take different roles in the meta and may get a spot in someone's team. I've been a fan of Nidoking's from the times it didn't need a Moon Stone to evolve, so my views may be biased, but from a competitive standpoint it needs those boosts to be a threatening pokemon in the meta. Don't worry that it gets overpowered, because it won't.
For reference see what boosts Metagross, Slowbrah and Sableye received. A Mega needs to be a better version of its original self, so a fast Nidoking with adequate bulk and ability to hit in both spectrums is a nice idea that shouldn't be overlooked. Usually people go all out when creating a mega, turning it into the most broken thing they can think of. Here we are restraining ourselves too much in fear of making it OP, and end up with not much added. Sure, EQ hits a lot harder now, but it's small things that take a pokemon from "meh" to "wow" (while keeping it balanced ofc).
It may even work as a future reference point. It sure has potential.
EDIT: I found a video with the exact same creation