While iTunes and Quicktime may work like a charm on their native platform, they cause all kinds of pain on Windows.
1. Because they are ported, instead of built from the ground up, for Windows they are highly unstable.
2. Removing them practically requires a re installation of Windows.
3. While not true anymore, iTunes used to only provide DRM music. That in itself is enough to shun it forever!
Whenever I come to a page that says “Extra Plugin required” and says I need Quicktime, I immediately leave the site. If the website can’t use a standard format with a reasonable Windows interface then they don’t need my business.