These zealots often seem ignorant of basic computer security, believing that Firefox will prevent viruses and spyware from infecting their computers, when in fact, Firefox is merely a browser and is not a universal panacea. If Internet Explorer is coupled with the freely-available security updates, it becomes as secure and more stable than Firefox.
Although it may lack the bells and whistles of other browsers, as an internet browser, Internet Explorer performs its job adequately.
Can be insecure with its default settings, but tieing them down virtually eliminates some, if not all of the security problems that people complain about. Unfortunately the reputation for spyware comes from dumb users who download shite like smiley central or are dumb enough to "YES" or "OK" to everything that pops up on screen.
Bashed by geeky open source zealots and Mozilla anoraks frequently who often over-exaggerate the truth in order to push their alternative.