"Security problems of the same magnitude as .ida buffer overflows, or
MSRPC buffer overflows exist in unix programs like Sendmail and others.
Why hasn't a worm materialized for this problem?"
"The scalper worm didn't effect nearly as many hosts as msblast did.
Why not? Why did the scalper worm seem to die out, yet wormwatch.org
still records many hits from much older worms like SQLSpida and Nimda?"
And I guess you can generalize and ask why the Windows "culture" generates
so many problems of such a magnitude, that last so long? My home office
web server got a Code Red hit on Sept 19th 2003, for example. Other computing
cultures (Unix, Mac, etc) don't seem to exhibit this. Why not? Shouldn't
we focus our efforts on figuring out what aspects of Linux or Mac cultures
keep epidemics from occuring? It's certainly a waste of breath to point out
that OS X has horrendous security flaws when none of them turn into grotesque
epidemics like Sobig.f.
To extend your "wooden house" analogy a bit:
In a city made entirely of wooden houses, a single house fire is way more
likely to level the city than a in a city where a mix of wooden, brick
and vinly-sided houses. Having the occasional brick house mixed in with
the wooden houses provides a lot of resistance to a whole-city conflagration.
It doesn't provide absolute immunity from fires for every house in the
city.