I have 40,000 on my '96 1100 Shadow. I just use it for the longer rides. I keep the miles down by riding my bobber to work and shorter trips.
I just heard an older (1980s?) 1100 Shadow with 250,000 miles on it, so they do last. I think it was on Youtube or one of those video sites.
My friend put 100,000 on his Harley Electriglide, but had the heads re-done at 50,000. The bottom end is sounding like it's ready to fall out any day now.
Alot of the metric bikes are very capable of getting high mileage on them, but it seems people get rid of them for various reasons, before they get too high. Some just don't have faith in the engines. If kept on a rigorous maintenance schedule, these bikes are tough as nails.