Many websites had to be specifically coded for IE as it wouldn't render correctly many basic parts of HTML/CSS.
Was IE6 demonstrably less compliant than other contemporary browsers? I recall - similarly - sites that were "Best viewed in Netscape Navigator at foo x bar resolution."
Also Microsoft would unilaterally add proprietary features
IIRC, IE6 added XmlHttpRequest, which - though there were other workarounds to accomplish the same thing - enabled AJAX.
Do not other browsers even today add their own features (e.g. browser-prefixed CSS properties) prior to standardization?
...and tie their software to it e.g. Outlook/Sharepoint
Do not other browsers even today add their own features (e.g. browser-prefixed CSS properties) prior to standardization?
Okay, that's definitely bad.