So, what do folks think are the things that attract someone to a ruleset?
I, personally, don't think it's the mechanics.
I think it's the setting.
While we have many passionate "Just rules, no setting" advocates here, but look at GURPS Traveller.
Obviously, GURPS is a "generic ruleset", by definition.
So, the "traveller" part of GT is, basically, setting. It's Lorenverse Imperium.
Most of the books tied directly to the Imperium. The Alien Races describe the races of the Imperium and surrounding environs. Behind the Claw, Rim of Fire, and Sword Worlds are all about the Imperium.
First In is about the IISS. Far Trader is the economics of the Jump model, not tied to the Imperium per se.
Raw Gurps, Gurps Space, Gurps Vehicles -- those are generic. They're "just rules".
But then consider what (most) every other RPG out there is selling. Not mechanics, at least, not "just" mechanics, but mechanics applied to some domain -- whether it's Zombies, Aliens, Orcs, Megacorps, Hackers, or My Little Pony.
T5 Lite doesn't do anything. Like GURPs lite. They don't do anything. They're great aids to get players rolling. But pretty much nobody just buys mechanics. Especially not impulsively. They buy fantasy, a place to escape to.
I'm curious how well The Traveller Book and Traveller Adventure fared. Because the book was complete, and the adventure was rich and detailed.
If you want to make a "Traveller Lite", bundle it with something like the Traveller Adventure. A light weight campaign that shows off the Imperium over about 6 weekly sessions. That would give players about 2 months of play. It gives them a fantasy to project in to, places to go, things to see, things to do, and mechanics to manage it.
As the GT page says "Marc Miller's Traveller is one of the most fully realized game backgrounds ever created . . . a vast empire of over 11,000 systems, with a turbulent history dating back thousands of years."
So, show it off! Run the players across the Marches bouncing off of some Aslan and Zhodani while trying to get a USB Thumb drive stolen from a Noble to Norris.
Settings sell, rules don't.