I follow, irregularly, the Retrogrouch blog, and he has a post about it called, "Hydraulic Shifting? Why?". From his post:
Cables are too simple for some people. Light. Simple. Easy to understand. Easy to fix. Replacing a damaged cable, whether for brakes or shifters, is an easy job even for an inexperienced home mechanic.
Can't have that, can we?
Even now, as hypesters are trying to convince us all that the future is electronic shifting (and that future is NOW!), oval chainring maker ROTOR Bike Components is releasing a new different technology -- hydraulic action shifting, to complement hydraulic brakes...
I don't know -- the "disadvantages" of a cable system, to my mind, are well offset by the simplicity. And cables themselves have actually improved to the point that the old notion of cable stretch is practically a non-issue. In fact, it was never considered a problem until the advent of indexed shifting -- in the days of friction-only shifting, who even noticed that the cables stretched over time?
This friend, as we Quakers say, speaks my mind. I know that most of my riding companions do little of their own maintenance, so complexity may not be an issue to them. But I also know that many of them, if they will be honest, could get as much riding enjoyment, and as much health benefit, out of lower-end bikes than they actually ride.
I've got two bikes, both of which I built from parts. I built them with longevity and cost in mind (I am not wealthy), and to suit my own riding style. My "fast" bike, the Yellow Maserati, has a titanium frame, SRAM Rival shifting system (because I got a great deal on it at the time), and Cane Creek brakes. It's light enough, but it's not really light - but it fits me well, and I can get it going fairly fast, especially up a hill. A minor savings in weight would not make a noticeable difference in my performance on that bike.
The other bike, the Krakow Monster, was built partly as a response to this technical creep of frame materials and parts. The frame is a Surly CrossCheck; it's chromoly steel, and it's heavy. The bike has cantilever "vee" brakes, which are the best modern braking system for rim brakes. But the shifting system is friction levers on the downtubes. I've made it up with 30mm tires (they will probably be wider in a future incarnation) and a rear rack, and I take it on towpath rides and any club ride rated C+ or lower. So far, I haven't had trouble keeping up.
The Krakow Monster is well over 30 lbs. fully loaded, with two water bottles and the 100 in3 seatbag I use. And it will go up Coppermine Road. Like this. That's not a bad pace, for a 60-year-old rider on that heavy bike.*
I don't need electronic shifting. I certainly don't need hydraulic shifting. I don't need disk brakes; I rarely ride in conditions wet enough to demand them, and I don't ride the screaming downhills that make heating up the wheels and tires by riding the rim brakes a hazard.
I can take my bikes down to parts and rebuild them (and I do). I love the mechanical systems that actuate the shifters and brakes. Cables, levers, cams... there's a steampunk feel to them.
My bikes do everything I need them to do. I don't need them to emulate racers. I don't need them to feed my desire for the latest gadgetry, or expensive toys. If that's what you want, fine. But expensive, cutting-edge gear doesn't need to be the norm for a 14mph flat, social ride in Central Jersey.
*Some of my fellow riders would like a lighter bike; at the same time, they never ride in the drops, and seldom change the chainring in the front. These riders would do as well with a single chainring in front, and nine or ten gears in the back, with a single shifter, on a bullhorn handlebar with no drops (the brakes could be set up the way they are now, or with mountain-bike-style brakes). That would present a substantial weight savings. But it wouldn't look like the standard road bike, so I doubt anybody will do it.