I've been seeing more drastically gummed up carbs in the last 20 years, but it's always been due to vinyl or urethane fuel lines or more drastically kreme coat tank liners.
I let my bikes sometimes sit for a year or more if I'm working on or testing one of the other bikes, and haven't really had any gumming issues. When I open the carbs I only see a very light fuel stain and maybe a small dot of super-fine rust in the bowl... just like since the 70's.
I am also in a pretty cold-winter climate. It's only hot here for a couple months.
