Is anyone concerned that by refusing to accept an end to Hubble that
we are really teaching mission designers and evaluators to avoid
astronaut serviceable projects in the future?

I'm not sure what the post-2010 lessons are, assuming that shuttle
retires on schedule. I expect astronaut serviced platforms (except
perhaps on ISS) are probably dead for the time being, unless we get
cheap and reliable access to orbit (a la America's Space Prize, for
example).

It seems to me that we should rationally and dispassionately deorbit
Hubble, and move on towards launch of the next optical space telescope

That's the problem. Progress towards future space telescopes has been
pretty slow. Webb has experienced cost growth and replanning and
isn't due to launch until 2013. In the ultraviolet, there is nothing
going on (that I know about).

I would prefer a series of space telescopes rather than One Big Space
Telescope (for one thing, a single telescope never has as much
observing time available as you'd want), but it is far from clear that
deorbiting Hubble would do much to advance that cause.