My 5.5" SRH weighs less than my 5.5 RH, both 45 cal. My 357mag Redhawks weigh more than my 7.5" SRH's... The weight complaint is either visually driven misconception, an exaggeration of imprecise published specs, a difference in grips, barrel length, or bore diameter, or simply an excuse to prefer the traditionally styled Redhawk over the "unique" Super Redhawk.
I'm not one to stand against pistol cartridges, or even rifle cartridges, chambered in revolvers, as I've thoroughly enjoyed 44-40, 32-20, 9mm, 45-70, 30-30, 22 Hornet, and 17 HMR revolvers, but I do believe in a responsible balance between weight and horsepower. The 10mm might stand tall among the munchkins in pistol land, but doesn't even make it out of the qualifying heats when compared against revolver cartridges.
I still don't care for it's design.
When it comes down to this subjective opinion, then by extension, the 454C and 480R Super Redhawks "don't make any sense" to those folks - it's a style issue, not really weight or size, although it's convenient for them to use that as an excuse. If the style of the SRH doesn't suit a guy, fine, but that has absolutely nothing to do with the 10mm.
It seems like more and more guys are trying to hunt with their 10mm autos, and the SRH certainly is better suited for such than a Glock 20 or 1911. Ruger's running their 10mm SR1911, so the SRH is a pairing in their cartridge line up. Guys buy Glock 20's and 10mm 1911's with hunting in mind, which doesn't make sense to any of us in the real world who have ever hunted with handguns either, so giving those guys another option obviously made sense to someone in product development.
Does a short barreled, birdshead grip 44mag make sense in the market? Does an 8 shot, snub nosed, heavyweight 357mag make sense? Does an overpriced piston driven AR-15? A 3" adjustable sight polymer frame 38spcl? On the surface, from a practical standpoint, not really... But all of them have sold relatively well. The 10mm SRH makes as little, or as much sense as any of these.