I personally also really like the factor you mention with interoperability between systems and different web pages if the content is in well-formed XML.

I definitely agree about Blogger and other companies that take that stance.

Then, of course, it’s always the discussion of what code is actually future-proof.

The invalid markup prevents their system from being future-proof, and from being compatible with any other system. Invalid markup cannot be integrated with other applications, and in that sense, it’s a potentially gigantic issue. What if Blogger suddenly wants to mix their service with some application that has become insanely successful? They would now have to convert their entire content database for it, and the longer they keep this attitude up, the more they are undermining their own freedom to expand their services to other applications.

Taking accessibility into respect is definitely one of the way to influence decision makers.

Another selling point to persuade the people making the business decisions, is saving money. If all code is correctly written, it can be:

a) Easily understood by other developers.
b) Lifted into another web page as sort of a snippet and it will work and not break that page if it’s well-formed (this is common in portal solutions).
c) Ready to be migrated into an XSLT file, no conversion needed at all if it’s well-formed XHTML.
d) Forward compatible (like Box mentioned above) in that sense that it will work on other devices such as cell phones, PDAs, Digital TV boxes etc, if it is correct XHTML (unfortunately not forward compatible with XHTML 2, since that won’t be backwards compatible).

These reasons are about making development faster and more flexible, hence saving money for the company.

Others look only at the visual aspect. As long as it looks good, there’s no reason to fix anything, because it’s not broken.

Since I’m firmly in the techno-geek camp, it would be easy for me to regard the second (far larger) group as lazy or superficial, but that’s unfair. It’s a difference in perspective, and I don’t think either group can claim to be ‘right’.

I work closely with non-technical people, and their ‘no need to do anything that makes no visual difference’ attitude was hard for me to handle at first. It still is, at times, but I’m learning to accept their point of view. Of course, I still nag on them to fix these things, because even though the shortcomings may not be visible to them, they may be for others. It’s an accessibility issue.

As for commercial corporations, of course they won’t spend any time and money unless they have to. Our only way to influence them is to ‘vote with our wallets.’ Don’t buy or use products with poor quality. That’s often easier said than done, though.

That’s the hard part about it. I wonder what the future web browsers will be like, if they also will rely on error handling for most web pages or if they actually will demand more well-formed code to work.

Also, I hope the discussion about and greater demand for accessibility will bring more correct code.

I’ve come across all to many companies / developing consultans that don’t even prioritize, they just don’t care about it. “As long as it works for the big crowd” seems to be their position in the matter.

The companies (and we) need to change the attitude against this, and start developing code that has a future in the next generation of browsers, careless if the browser is in a PDA, PC, Mac or Digital-Tv.