This summation is probably the best reason (s) that I have seen:
In my opinion, if you don’t have overriding compatibility or support issues, there are several good reasons to prefer alternative browsers such as Firefox or Google Chrome to any version of Internet Explorer. For starters, both Mozilla and Google have generally been faster at releasing updates to security issues than Microsoft. If it’s true that Microsoft knew about this issue for more than four months before delivering a fix, that’s a big argument against trusting IE.
And, right or wrong, security by obscurity is real. Although other browsers have serious vulnerabilities, Internet Explorer is the one with the target on its back. Those other, less popular products might be targeted someday, but at least for now most in-the-wild exploits simply don’t work on anything except Internet Explorer.
