You keep saying this ... but as you can see from just this thread, it is an idiosyncratic definition.*
We are just going to have to agree to disagree here. I get that in this thread, there is largely that definition being used. I get that in places like Itch.io it is common. But I have been using rules light to communicate what I am talking about here without much trouble for nearly 14 years online
I have played for just as long as you, and I am perfectly comfortable understanding that "rules lite" refers to a specific category of games, and ones that exclude games that have rules that run to 100 pages.
Here I would agree in that 'lite' is something I think refers rather specifically to what I would call a micro-RPG (something that can fit in a pamphlet or is under 10 pages).
To the extent you wish to communicate something to people, you might want to use the common usage of the term employed by others. If you do not wish to communicate to those people, then you are welcome to continue to use your own definition; that said, this isn't exactly a jargon thing. I provided you one place (itch.io) as a single example. If you bother looking around, you will see that this is a common conception.
Again, I can see people have been using that. I just don't think it is something like the majority of the hobby.
For example, you can also search DriveThruRPG for games that are "rules-lite," and you will not find 100 page booklets of rules in there.
Again, the distinction here is 'lite' versus 'light'. And 100 is the soft cap I am using as a guideline. I am saying something 100 pages or less, in my mind is likelier to be rules light. If you look up rules light/rules-light, you will see plenty that I think are in that range (and certainly many on the lower end too). Here is just the first several when I search:
Yarr! The Rules Light Pirate RPG: 71 pages
Folklore (No page count given but will assume it is on the very short end for that reason)
Journey-The Rules Light, any setting RPG (no page count given, hard to tell from preview how long it is)
Monophobia: 15 pages
Bibliophobia: 17 pages
Cyberstreets: 75 pages
No One Owns the Skies: 4 Pages
Dept. X: 5 pages
Submerged: 15 pages
Coyote and Crow: Rules Light Adventure (no page given but looks like a starter rules set so assuming on low end of page count)
Zombified (Very Rules Light): 34 pages
Power of 10 (P10) A rules light RPG: 158 pages
FIRETEAM: 46 pages
You may attempt whatever prescriptivist approach you wish, or argue that you have a private language with others that allows for this relative classification, but in the larger discourse, these words have a meaning ... one that you choose not to use.
I don't think I am being prescriptivist at all. I am using a descriptive definition based on what I have seen used. If you put my feet to the fire on it, I would say rules light probably covers a range that includes what you and I are both talking about (and I might make the distinction I did earlier of lite or micro or minimalist to refer to the much smaller rules light games in that category)
*Again, it's been pointed out repeatedly that it's also a meaningless one, given that it's relatively simple to point out a large number of games that are far under that threshhold that even you wouldn't classify as rules-lite. So we are left with the uncomfortable notion that "rules lite" is something that you know when you see, and it leaves the reader with the idea that it is somewhat of a goldilocks definition as opposed to a category of games that actually exists and does, in fact, have a very ... um ... light approach to rules.
Again, I am not saying it is the only thing. I am saying being 100 pages
or less isn't disqualifying and it is one possible indication.