I agree, and I have actually been pondering recently that the SG has never gotten the same amount of love from guitar reviewers as the Gibson Les Paul, the Fender Stratocaster or the Fender Telecaster. Even if we only go by the guitar reviews posted at the Andertons YouTube channel, then they're constantly bringing up Strats, Teles and Les Pauls, but rarely ever an SG. Even an ES-335 gets more love.
But SGs have indeed been used by many notable guitarists in the history of the electric guitar. While he was in Cream, Eric Clapton played an early 1960s SG Standard called Emily, which had been painted by a Dutch group of artists collectively known as The Fool. Carlos Santana played an SG Special — technically, a Les Paul Special, because it was still one of the early 1960s SGs marketed as Les Pauls — at Woodstock, and for the recording of (among other things) "Samba Pa Ti", as well as that he played a white three-pickup SG Custom later.
Jimi Hendrix also owned and played a (late 1960s) white SG Custom with three pickups — the Gibson Custom Shop is currently offering a replica of that guitar. Terry Kath of Chicago also played a white three-pickup SG Custom. Barry Goudreau exclusively played SGs during his time in Boston, and then later in RTZ. The legendary jazz-fusion virtuoso Alan Holdsworth also played a three-pickup SG Custom for a long time. Tony Iommi of Black Sabbath also only used SGs. And of course, the 12-string/6-string twin-neck Gibson EDS-1275 that Don Felder used on "Hotel California" and that Jimmy Page used for the live renditions of "Stairway To Heaven" is based upon the Gibson SG design.
Still, somehow the Les Paul has always been and continues to be more popular. And yet, sonically there isn't all that much difference between an SG and a Les Paul. There is some difference, yes, but it's only a small one — so small that it probably disappears in the studio mix. Furthermore, an SG is much easier to play than a Les Paul, because it's thinner, significantly lighter, ergonomically contoured, and you have unimpeded access all the way up to the 22nd fret.
Myself, I own three SGs, and I'm quite happy with them, although I will admit that I bought one of them as primarily a collectors item and that I haven't played it much yet. It was a 2007 "Guitar of the Week" limited-edition model of which only 400 were going to be made for the whole world, with three narrow single-coil pickups with "rail" pole pieces and a six-way rotary pickup selector switch. It wasn't terribly expensive — actually, only about the price of an SG Special at the time, i.e. about €1'200, hard-case included — and given that it was only going to be made for a week, I immediately ordered one. I think I've shown it to modwiz in one of our video conferences.
My other two SGs are a 2007 SG-3 model that was not officially a limited edition but that was nevertheless in production for only two years — with a similar configuration as the one mentioned here-above, but with three '57 Classic humbuckers, gold-plated hardware, and a small "early-'60s" pickguard instead — and then my very first ever Gibson, a 2002 SG Special "Pete Townshend Signature", with dual P-90 pickups and a compensated wrap-over bridge/tailpiece. And I'm sure that I did show that one to Radagast, because he's a fan of P-90 pickups too.
A tested battleaxe, yes, absolutely. But also a bit of an unsung hero. And that's kinda sad.