The Victorians understood the interest of normalisation and propelled Britain way ahead of the world partly thanks to this. I work for an industry -construction industry- which is far less high tech than the IT industry and even "thickos" like us know that normalising stuff equates to profit but MS refuses to do it. They are just living in a parallel world and have no consideration whatsoever for their stakeholders.
The building blocks of IT are reasonable well standardised (although not perfect, as these examples attest) but that's as far as it goes. The majority of IT stuff that people use are built from these components in their own unique way.
The deeper problem is that the underlying standard is ambiguous and limited, and gets interpreted in different ways by different people resulting in browsers that work slightly differently.
The same argument can be had for the construction industry. It's not as if the construction industry has a 'standard reference house'. Almost every house is unique at some level (pipework, layout, etc), even in a row of terraced houses.
On top of that you've got the problem in that the standards lag behind implementation (you only need to look at the Browser support for HTML5 as a good example). Can't do certain things using HTML4? Stick up a Flash applet and say bollocks to anyone who can't run Flash. (Replace Flash with DHTML, AJAX, Silverlight, Java, ...).
HTML4 didn't do everything (easily) that MSFT wanted for Outlook Web Access and so they implemented their own extension in their own browser to solve the problem. What would have been bastardish is that if they'd prevented non-IE browsers from using OWA at all, instead it will still run but with slightly reduced functionality. Waiting for a new and improved standard that implements everything required is out of the question as they'd miss the boat by *years*.
By the time HTML5 is finally ratified as a standard there will be applications/uses for which it is obsolete. There will be numerous extensions and not all browsers will be able to cope with everything. It's just the way IT works. Designing and implementing stuff is much more fun than writing standards. Designing stuff with an open mind is more fun than designing stuff with one hand tied by restrictions imposed by the need to exactly follow a standard.
The web didn't become what it is today by following standards. (Whether you think that's a good thing or a bad thing.)