Agreed on 90% of What you're saying. the 2x 5%'s that I differ on are that Shadow the Hedgehog (game), Sonic 06, Sonic Boom, and Big the Cat are imo the worst things to ever happen to the sonic franchise. I'd even go as far as putting SA2-On Tails because he lost almost everything that made him iconic
the other 5% of me just remembers as a kid, besides being virtually the only person i ever knew that played Sonic CD, that Knuckles (and Metal Sonic) were the epitome of what I went for vs. strictly sonic. Now don't get me wrong, entirely oppinion based and S1 all the way to SA I loved Tails just as much, but he felt like a back-seat/little brother character and knuckles to me always fit the bill as the up-to-par yet alternate Sonic that had a lot of things going on in comparison (to sonic, not tails), and I think besides Sonic Adventure (and again, Sonic CD) that S3&K was the most played game in the franchise throughout my entire life.
Not saying I agree with Knuckles, although I welcome him as the "cant jump as high or run as fast but can run through loose walls climb walls and glide whereever the **** " Alt. to a Sonic Character I could've hoped for, but that If knuckles needed any kind of "pull me out of the gutter" type pull, having him be the Falco to Sonic's Fox gets my 100% approval.
TL;DR: Yeah, I can see that. *Shrug* I can dig Knuckles.
Besides,