When Sheldon wrote that stuff too most TI bikes were built with standard size tubing found with steel. Litespeed did make a bike (can't remember the name of it back in Sheldon's day, the Blade?) that used larger diameter tubes that riders said was a very stiff ride. So Sheldon never rode a TI bike made that way. And modern ti bikes are now constructed to be less flexy, but still springy enough to make the ride comfortable.

If a steel bike is taken care of it won't rust. I have several steel bikes and most of them are at least 23 years old and one is 27 years old and that one was rode a lot by me including riding it in the rain. I use to own a 79 Schwinn Traveler I bought new to ride on the wet sand of So California Pacific ocean, which meant it got drenched a lot of times with salt water! All I did was go home and hose it off but that's it, and that bike sat outside of my apartment where it got rained on. Then I stored the bike for about 15 years and when I moved I pulled the BB out to check for internal rust which there was some, but still usable, but I decided to leave the bike behind since it needed new components because the salt corroded the aluminum and there was some surface rust as well. But your talking about a lot of abuse and the darn frame wasn't rotted. So I have no problem with using steel