I dont consider myself a Linux zealot, but thats an argument for a different thread. I will lay out my basic reasons for saying "IE sucks" below.
1) ActiveX: It doesnt matter how many "warning dialogs" or "security prompts" that are layered upon this thing, it is still one of the single greatest security holes in Windows. I mean, geeze, ActiveX applets can gain *complete* access to your system, often without the slightest warning, simply by you accessing a website. And any warnings that do appear are simply dismissed by most users - they dont give a flipping damn about security, they just want access to whatever the site promised; games, silly screensavers, porn, etc. Once an ActiveX object loads, it opens the door to any number of other programs (spyware, keyloggers, rootkits, you name it). And since most Windows users run as Admin (sadly, this is true even corporate environments), these programs can easily gain access to the complete system.
2) "JScript": Microsoft's debauchery of Javascript. As a web-application developer this hits me particularly hard. Fortunately, most of the apps I develop these days are just internal apps for my company, which is mostly Firefox/Mozilla users. To have full cross-browser support, its usually required to write the application twice; once for IE, and again for everything else. The same is true for IE's CSS "support".
3) Integration: Because the core IE engine is used in Windows itself, as well as dozens of other programs, compromising the browser enables direct access to the rest of the system. Granted, if proper privilege restrictions are in place it would limit damage to only those areas that the users has access to - the users own data, for example, but thats little comfort if all your data gets wiped out; or worse.
A recent example: This happened about 2 months ago. At work, I had just finished setting up an XP pro SP2 box. Every security update, Trend Micro corp. antivirus, the works. The security settings in IE were turned all the way up. By any measure, it should have been fairly secure.
A co-worker of mine needed a serial for a program. For some reason ( I guess because I was sitting in front of it), I used that XP box to search for the serial instead of my Debian workstation. The first result in Google I clicked on, the *first* one, resulted in a popup storm and numerous pornographic click traps. (I followed the same link a few minutes later with Firefox on my Linux box - no popups, no traps) Now, these popups occurred despite IE SP2's built-in popup blocker being set to full.
I pulled the plug out of the back of the XP box the moment the popups occurred, but I wasnt fast enough. Upon reboot, the machine was infected with *3* pieces of spyware. From one link. With full security settings in place.
Now, granted, most users dont go searching for serialz. However, many, many users do surf for porn and various other things on a nimiety of malware-infested sites.
If you visit a cheap whorehouse in Tijuana and don't wear a condom, you deserve everything you get. Surfing the Internet with Internet Explorer is no less risky than unprotected sex in a cheap Tijuana whorehouse.
And when the moment is right, I'm gonna fly a kite.
