I mean, I like Microsoft and Windows as much as the next guy, but geez, as soon as IE had 90%+ marketshare (due, lest we forget, in some measure to illegal behavior) Microsoft just let it stagnate. That alone should clue you in to how Microsoft feels about web browsers.
I actually hate Microsoft. A lot. I work in web UIs, and the bulk of my frustrations come from having to work around IE's shortcomings. My personal computer has been Microsoft-free for the past 2-3 years, as well as a period in college, and in-between was only used as a Windows host for a Linux virtual machine. I try to avoid using Microsoft products whenever possible, I hate the company and would never think of working for them, and I would be rather glad to see them broken up.
But I try not to let my feelings about the company color the way I see the accomplishments of individual employees of the company. And whatever my personal feelings, the IE team accomplished a lot between 1995 and 2002. Netscape was as dominant in 1995 as IE was in 2002; in those 7 years, their positions reversed.
You can claim it was due to extreme marketing, but I was more than capable of downloading Netscape for myself, I was a die-hard Netscape fan up until 2000, and yet eventually I had to admit that they lost because they were stupid and the IE team was better. Netscape 4.7 was slow, it had poor standards compliance, it crashed a lot, and it refused to view a lot of really popular websites. Netscape 6.0 had an incredibly crummy interface that seemed like it was designed to take you to their portal page and trap you there. IE kept getting faster and more stable from IE3 to IE6, and it introduced innovations like XMLHttpRequest that later formed the cornerstone for GMail and Maps.