Personally, I think there's an important lesson here, and its the same lesson that polymer is learning as it stumbles around trying to convince people to use it. Most people don't actually derive much benefit from writing custom UI widget primitives. Certainly, that's a useful thing for a UI toolkit builder to be able to do, but tangibly, for most people, it's not actually useful. I don't have time to invest hours im…
One of the very real issues WebComponents solve is encapsulating the component functionality and styling away from everything else in a typical web page; you know, the basic separation of concerns stuff.
Certainly nothing that Microsoft proposed then has today's comparability and flexibility of today's offerings.
Microsoft didn't lack good ideas back then when they cared about the web; they were clueless about interoperability across devices and platforms. (IE for the Mac had a better but different rendering engine than IE for Windows did.) And because of their monopoly status then, they weren't to be trusted.
I also want to correct something the article mentioned, that Netscape was irrelevant back then due to Microsoft's cool features--not true. In fact, on any big project, developers had to essentially make two sites--one for Netscape users and one for IE users.
The "new" Microsoft it much better with getting their ideas out and working with other companies.