As for the question of what is wrong with road tourers that they carry all that stuff, I think I have some perspective on that one. I came to bike touring from a background in backpacking and mountain biking. When I was gearing up for our 2002 cross-country tour, I did a lot of research and got involved in a lot of forums, etc. I was going for a, well, not ultra-light but light-weight set-up to begin with and a lot of people just seemed to think that was silly.
Overall, it comes to 3 issues: First, as WalksOn2Wheels just said, the weights 'on your bike not your back' so it 'doesn't matter'. I still remember reading up on a woman from MI who took a full-sized wok and a teddy bear on every tour with her. A freaking wok! This was a small woman, think about how much farther she could go, or how much more energy she would have at the end of the day if she brought her 60 pounds of gear down to 40. In some ways touring is a 'counter-culture' which rejects all that is associated with racing. And so, there's nothing wrong with more weight.
Which brings me to my second point, bike touring is a very traditionalist pursuit. And what worked best in the 1970's surely works best today. Mountain bikers and ultra-light backpackers are more willing to embrace new technology in order to make their experience better. For example the simple hydration pack means you don't (may not) need to carry your water bottles in your frame, which makes room for a frame bag... and so forth. (I will say however, that touring without a pack on your back, especially in hot weather is soooooo nice.)
Third, there is a very strong 'be ready for anything' attitude among road tourist. People who ride nothing but paved roads in the United States seem compelled to gear themselves out for a multi-year trek around the backroads of Africa. I think this is because all of the 'guru's of the sport are long distance riders, and often riders who travel abroad, and so everyone wants to 'be like Mike'.
All good points. It definitely is a counter culture to the "racing" roadie sub-culture. If you go to one forum, people are willing to spend a grand to drop 150 grams. If you go to the other and you even breathe a word against panniers, they make fun of you and your sweaty back. I did a post when I decided to ditch my panniers, and this is before I started entertaining the idea of actually wearing the backpack, and pretty much everyone had something to say for panniers and that I was silly if I thought 5 pounds difference would matter.
It's as if heavy panniers in the touring/commuting world are the "manly man" scale equivalent to double cranks in the roadie world.
Not only that, but before I bought my Talon pack, I was searching BF forums and almost every post that came up regarding advice on backpacks, someone had to chime in with something to the effect of "something to mount on your rack, like panniers."
But hey, in the end, I just hope everyone is having a good time riding their bikes. We like to poke and prod at Fred's and recumbent riders and they in turn lash out at the roadies and nobody seems to like the hipsters on fixies. But who's keeping bicycling alive? All of us.
