A "scam". No. Not by any definition of the word.
Carbon fiber is easily capable of being tuned to give a lively ride, a compliant ride, an ultra-stiff ride or a good mix of all of those characteristics. It can also yield a frame that is torsionally very rigid. It can be manufactured to be more aerodynamic than steel, aluminum or titanium. It can be made lighter than steel with complete carbon fiber bikes coming in under ten pounds available at your local Trek dealer if you have the money and desire.
I do agree with you that steel (and titanium) are the most durable materials for a bicycle frame and that steel, in most cases, offers the best option as far as repairability goes. The rest of your list can easily be matched or exceeded by other materials.
Comfort: I've had steel bikes that rode like gas pipe 'thudders' (Columbus Cromor, in particular, was a very dead tube set used in two frames I owned and raced). Titanium, in my experience, is a very comfortable material to design a bike frame with. Without losing all semblance of liveliness it can be engineered to soak up tons of bumps and road imperfections and makes a great all-day bike. By the same token, designing a comfortable carbon frame that still exhibits sufficient stiffness to win World Tour events has become ridiculously commonplace.
Speed: ??? All frame materials are 'fast'. Given a good motor, reasonable aero shaping and angles for good handling any and all of the common frame materials could still be competitive at any level including the professionals.
Reliable: The word can mean something close to "durability", but if used to describe something like the day-to-day requirements of an average fit guy out ride 30-75 miles maybe 3 to 5 times a week...my low-end carbon frames have managed to do everything my steel and titanium ones did...including break. Yes, I've broken both steel and carbon frames and I can tell you story after story from back in the glory days of steel frame of friends, team mates and competitors that had steel crack, split, come un-brazed and just plain fail. It wasn't a time of all drippy Italian paint jobs and chipping decals...
Style: That's in the eye of the beholder and frankly, there's plenty of fugly steel bikes out there. Overall, I've found eye-pleasing designs in all frame materials, save for wood. I just find it (personally) unsuitable in the styling department.
Bling: Again, as much as I love chrome Nervex Professional lugs, chrome Campy bolt-on pump umbrellas, a chrome Campy double-tunnel, stainless steel spiral wound Campy rear derailleur cable housing, polished Cinelli articles, black anodized track pedals and pantographed EVERYTHING tossed on a chromed up Colnago Profile CX with indented tubing and a 12-step paint job clear-coated to an optical depth of 4"...again, however cool I believe it to be, is not everyone's idea of bling.
Today, bling is dead sexy UD carbon, flowing aero joinery, minimalism in materials usage, electronic function with internal wiring (we used to call it "sano" back in the 1960's for a sanitary build of a car or hobby project), matte mixed with gloss, high-vis paint schemes, black components or painted ones have replaced the anodized and polish aluminum ones I used to buy. Stainless polished spokes have given way to black featureless ones that do not flash in the sun like my old DT's did. Today's bling probably does include documenting every minor and major technical feature of a frame with its own decal or set of decals. Even serial numbers now have devolved into some sort of bar code decal, but this reflects the younger generation of designers' builders' and customers' definition of what is showy I guess.
One thing that is not mentioned much is the weight comparison to the average steel frame and fork and even an inexpensive carbon frame and fork. I live in some fairly steep terrain, do a bit of climbing and I really appreciate the weight drop afforded by going to carbon fiber construction. As you said, maybe it's a placebo effect, but I'll take the dragging 3 to 7 pounds less up every of the many climbs I do in a ride as the biggest sales factor in my bike buying priorities. I deem it an advantage and I'll only level the playing field in playing 'keep up with the carbon equipped Joneses', but I'll take it any way I can get it. A flatlander probably will not see the need as greatly, obviously.
I still have a couple rooms stacked full of my well used and well liked steel and titanium bicycles and only four carbon bikes. I've was on steel starting in 1972 and have only been on carbon since only 2007, but with its known characteristics and perceived faults I seriously doubt that I ever return to riding steel bikes. I'm 61 and have been training and racing for 43 years. They had better hurry up if they want to get me another frame material...I ain't got that much time left!
Just my 2 cents worth and take it for what it cost you.
Regards,
CampyBob