How many of these vulnerabilities were due to Firefox itself, and how many due to plugins? Does it matter? If FF allows the plugins enough control over the browser to present a vulnerability in the browser, then that's a vulnerability in FF that they need to fix. Saying "oh no, we don't have vulnerabilities ourselves, we just allow vulnerable plugins to run" doesn't speak much to the security of Fire Fox. In other words, the cop-out doesn't fly. If FireFox is vulnerable to something another browser is not, i t has one more vulnerability than that browser, period.
Big Jeff, you appear to put a lot of time in on Slashdot. Do you do it for a living?
This comes down to how long it is. A cosmic string isn't the same thing as a string in string theory. A cosmic string is very long macro scale topological feature of the universe while a string theory string is a model for subatomic particles. However you can investigate cosmic strings in string theory leading to the theory of stringy cosmic strings of Vafa et al..
New systems generate new problems.