I hadn't quite thought of it that way, but I like your point. I played a Millenium's End game, and while the large quantity of realism they aimed for in combat was cumbersome to learn, it also provided an element of excitement.
Since spending a good bit of time sparring with Agemegos, I've come to see the games on sort of a continuum. Every game I can think of lands somewhere along the line; I own dozens of games and have played literally hundreds by now. So this was sort of revelatory for me:
Theater Story Game Mixed Format Simulation (D&D) War Games/Video Games
A lot of the games that get billed as RPGs and easily get converted over to video games, etc, are in the Simulation section of the continuum. D&D evolved from a war game, Chainmail, in the late 70s. It was a minis game that became more story oriented as it aged, then as it hit 3rd edition, with the addition of Feats and such, became very character-centric rather than "kill-it-kill-it-for-XPs!" Then with 4th, it regressed to something like a mix of 1st edition and 2nd edition, with all of the trappings of 3rd edition. Shadowrun, Palladium, Palladium: Rifts, etc, land here.
Then you get your mixed format games like WhiteWolf's traditional products, which use troupe play techniques (from theater) and a lot of characterization, backstory, social intrigue, etc. But they rely on the backbone of the system to keep players from running roughshod over each other. But its heavier on simulation than on theatrics. On the other side of the coin are games normally associated with story gaming like Apocalypse World or Dogs in the Vineyard, which have some system, but largely just to keep the details straight. Some of the LARPs land in here as well, dashed about in the mix.
Then you go off into Story Games proper, where it becomes all about the narrative, or emotions (Flowers for Mara) or impromptu theater. A lot less system if any really at all; mostly just a lot of handouts and background information to keep everyone's part of the story straight. Then you hit the almost purely theater end, where you get the hardcore LARP, historical re-enactment, etc. There are fake personas, costuming, social rules of conduct, but usually little written down. You may as well be playing a script.
But the unfortunate part of trying to make an online gaming solution is that we all, no matter which selection you put us in, recognize ourselves as some sort of 'gamer'... and so a product aimed at Gamers, well, it should be aimed at me, right? And you. And that other guy. But the people at the two extremes (Theater vs. War Games) are so far removed from each other that their needs are very different, and although you could do them on Roll20, you may as well just use a vid-conferencing system for the Theatrical types, and specially prepared sites for the war gamers.
Touche.
Eh, just my opinions. But it's nice to get a comp'd ego boost every now and then. :)