Nah man, Centrale's got a good point. I don't know if it's fair to characterize dissenters as just being in denial about having outgrown the series either, but I think you guys are hitting on an important question for video game fans...
Is it better to actively complain about a series going in a direction that you disagree with, or should you "check your privilege" to borrow a phrase and let the creators take the path they choose. Sonic has reached a point where the fanbase has become so fragmented that the team can ignore a segment and still have a fanbase left over.
For reasons that escape me and Shun-Di as well, this series continues to sell and, if you look at the Sonic Forces media out there it seems to be getting good response. To me, when I see the media surrounding this game, it seems like the confirmation of every joke any detractor ever sneered about the franchise as I waited for the developers to prove them wrong. I'll be honest, I'm one of the people who gave up on the series all the way back at Sonic Adventure 2. I honestly didn't like that game despite some of its strengths (which came as a shock since I'd LOVED the series up to that point), and I was only 11, so I can't say that I'd outgrown it. From there I waited for a game to appeal to me, and that honestly didn't happen until Sonic Colors, Sonic Generations, and Sonic Lost World (an awkward game, but I appreciated it). Prior to that, the games didn't look good to me and their scores agreed.
I'm excited about Sonic Mania, but a new Sonic game doesn't HAVE to be a Genesis throwback. I guess I'm just jealous of Nintendo fans in a way... Metroid, F-Zero, and Kid Icarus fans notwithstanding. When changes are made to the Mario and Zelda formula, they're logical and in keeping with the identities of those series. Now, I don't expect Sega to be like that with every series they've made -- they were always these awesome pop-culture junkie punks who churned out ideas as fast as they could, and I loved them for that. But Sonic (alongside maybe Phantasy Star, Virtua Fighter, NiGHTS, and Sakura Taisen over in Japan) is a series that deserves that Mario/Zelda kind of treatment.
How often have Mario/Zelda fans looked at the next installment and asked "what am I even looking at?" Once a piece during the GameCube years? How many of those fans "outgrew" the games?
Outgrowing or changing times get cited a lot when it comes to Sonic, but I honestly think that the character at its inception was as timeless as Mickey Mouse, Hello Kitty, Superman... whether the score of Sonic Forces is 5/10 or 8.5/10, nothing about it seems "timeless" to me. The best explanation I could come up with is that no one who was present at the character's inception is involved anymore.
Now, are my expectations too high? Sure! But the people who conceived the franchise did exactly the same thing, and that's what lead to some of the best games of all time; games that really have not aged.
I don't know -- you're absolutely right, ranting and raving doesn't help a thing, but at the same time, I do disagree with the notion that I've "outgrown" Sonic. I've recently played some childish games like Super Mario Galaxy, PaRappa the Rapper, Napple Tale, and We Love Katamari for the first time, and went "yeah, these is timeless. What a great game." I'd like to be able to say the same for Sonic, and I happen to think that the answers to getting back to that point lie in its roots, but honestly, (I swear I'm not saying this to be snotty) what the hell do I know?