Though, actually, I think it is a valid question.
You want statistical proof that the whole OSR phenom happened. I don't think that's necessary. If you have any proof that there was something else going on in the hobby at the same time that completely overshadowed it, go for it.
As an example, consider my second question - what counts as "backwards looking"? I see people claim that the move to simpler mechanics is looking backwards. I think that's off. If we are thinking the past few years, then we are talking 4e-era and onwards. Well, "backwards" from 4e there's the OD&D line, which I grant is simple. But it also has 1e, 2e, and 3e, none of which really deserve the title of "simple".
I don't think any version of D&D deserves the title 'simple,' not even 0e and certainly not 5e - it's always been a relatively complicated game, so, yeah, I'd agree it's off. But, even if we grant that 0e & 5e are simple and other eds aren't, looking back to 0e 'simplicity' is still backwards-looking, that intermediate backwards steps aren't necessary less complex, notwithstanding - it's just looking /way/ backwards.
Really and honestly, the past has *all sorts* of games in it. So, saying that a game is "backwards-looking" does not seem meaningful.
When 5e was being developed, Mearls &co said, repeatedly, that they were looking back to the prior editions and trying to achieve a 'classic feel.' So, yes, 5e was backwards-looking,
at past editions of D&D. What Traveler or RQ or WoD were doing in the past not being relevant. Likewise, whatever other games were doing in the 70s & 80s, recent re-boots of RuneQuest have harkened back mainly to RQ2. Storyteller has gotten high-profile 20th anniversary editions. Nor are they the only two classic games getting re-boots. The whole OSR thing is backwards-looking.
Sure, there are forward-looking indie games out there, but the big trend has been backwards-looking - and, probably, what industry growth that has been reported is being driven by that.
Has anyone really written out a list of the games that have come out in the past few years? I think it is a long, long list.
It probably would be. And it would have a lot of OSR games on it. But there's also the question of what games make a big splash - which is generally going to be biased towards new/innovative/surprising ones - and at what games are leading the market. Leading the market, right now, is 5e (backwards looking), PF (3.5 retro-clone), two of those '______ Age' games, also on the OSR 'simple'/old-school bandwagon, AFAIK, and the latest Star Ward licensee (and, even though it's not backwards-looking at Star Wars d6, mechanically, the Star Wars franchise, itself, has marginalized the extended universe and is harkening back to the original 3 movies in a lot of ways, too).
Or we can note that there are really only two big players - WotC and Paizo, and the only meaningful trend is that they both, with rather different design philosophies, seem to be doing well.
They are both crystal-clear examples of backwards-looking games. The only difference is how far back they look. PF looks back to 3e, a mere 8-16 years, while 5e looks back to the 20th century.
You see my point? I don't think anyone has actually presented a cogent view of "where the hobby has been going".
I see the point you're trying to make. I don't think you've come anywhere near supporting it.
*This is hardly a new argument, though usually I see it in the form of noting "old school" really seems to mean, "That stuff from the past that I liked," and wihtout noting that all the other new stuff one doesn't like was *also* represented in the same time period.
"Old school" is usually used to refer to the methods, maybe even mores, of a time in the past. In the context of gaming, that's the way we used to play D&D, not the details of the rulebook. And, it was a less connected world back then, so you didn't have a monolithic 'way everyone played D&D back in the day,' it varied with things like region and age group.
But, even if people don't have a clear or accurate or consistent vision of the past, looking back at it is a big trend right now. As demonstrated by the prevalence of that very argument you site.