Catbirdseat, part of the light and fast theory is that you are actually increasing your safety margin by spending less time subject to avalache danger rockfall etc.
You do make a good point that most people who are just starting out don't pay a lot of attention to lightweight gear when they first start out. I'm in the process of making much of my gear lighter. That said if i where to climb rainer via non techincal route with the gear i have right now i estimate my pack would weigh around 25lbs. Thats carrying a 4lb sleeping bag, 3.5lb pack, 5lb tent, which would stay in camp on summit day.
Since the orginal post was for training hikes, how about stuart via cascade coloiur and del campo. Theres a lot more out there but I have enjoyed both those.