How awful that Microsoft doesn't design all their products to meet the needs of their competitors. The nerve.
That's not exactly what they did. Web browsers identify themselves to the server; that's part of the protocol. If the browser identified itself as "Opera", MSN deliberately served up a broken stylesheet, different from the one it served up to MSIE, that made the page look ugly. When the opera browser was modified to identify itself as "Oprah" (there is no "Oprah" browser), MSN worked just fine. IOW, MS went out of their way to design their product to make their competitor look bad. Incompatible by design and intent.
The standards were there before Microsoft, and Microsoft even helped in their evolution after entering the browser market. IE is just an old, broken, non-compliant crappy browser, but because it's dominant people write to it instead of the standards. Sad, because for a while IE was IMHO the best browser on the market at one time.
Standards are there for a reason that has nothing to do with competition, but to keep systems communicating. However, Microsoft likes to use its power of monopoly to make what they do standard and lock everyone else out. Some standards are bigger than Microsoft, meaning that Microsoft can't mess with them, like TCP/IP, the basic protocol of the Internet. If Microsoft messed with that, it would be their machines left out in the cold because they do not dominate the router, switch and firewall markets.
Other standards like HTML and CSS are a little easier to influence. Others, like Kerberos are ripe for Microsoft's trademark "embrace, extend, eliminate" philosophy.
It doesn't matter who is breaking them, standards should be met or the computing community at large suffers.
Seriously if Ford and the four largest oil companies started adding something to gas that would stop other cars from working do you not think there would be public outcry?