One side effect of this carbon craze or need for speed is that the steel and aluminum frames that we like are available because someone is going out to buy the latest bike and selling off their old steed. I agree for almost all of us, the older bikes are just fine. That is why we have them.
I work with a guy that brought in his carbon fiber triathlon bike. I was impressed at the weight or lack of it. When I raced (back, in 1980), my double butted bike weighed 22 lbs with tubulars. I don't know what this bike weighed, but it was several pounds lighter than my bike and it wasn't even that cutting edge. Then again, it is a race bike and cannot do much else. There is always going to be a new and better thing out there. It doesn't make the old stuff obsolete or even less worthy.