Yep, good point.
However, Mozilla is updated by volunteers, Microsoft is not. This means it *can* be more agile.
And with linux...I remember when I was working at a computer "assembly" company that was kind of small, and we had assembled a cluster node of servers on a rack. My noob boss put linux on it, spent all day configuring the cluster node so that it would actually work, and overnight it was hacked and the whole system was hosed. They ended up bringing in a contractor to set up linux the right way.
