Before I begin, phrasing it as *XHTML* compliance is confusing the isssue.
HTML compliance (in general) is much more important. Going from html -> xhtml is an entirely different discussion.
However, since your post speaks mostly to compliance, let me answer that..
Hockey wrote:How important is this to you?
Critically important. Its like someone trying to sell a box with four wheels as "A car".
Its simply not. If it does not comply to the html standard,
it is not an html page. Its tag soup.
Now, as to why making a (compliant) html page is more important..
Hockey wrote:I personally don't care...I mean bother?
I presume you meant "why bother". So lets talk about why.
First and foremost, we are programmers, right? So think about how nice it would be to use part of your content in another page - like google maps. If they used non-standard html, you'd have to write a custom parser for every page you wanted to utilize. Stock quotes? Custom parser. Local Weather? Totally different custom parser. Talk about pain!
The current buzz about "Web 2.0" is about building sites using content from other sites, and providing your content in an accessible fashion to others to do the same. Just like unix, now on the web its "Do one simple thing, and do it well" - hence web api's like ebay, paypal, and google maps.
But thats just for development. Then there is the simple matter of
actually letting people see your content. If your site uses non-standard html, I guarantee there are people that can't read it. Whether its people using a screen reader, braille devices, or using a parsing proxy, you are preventing people from seeing your content.
Until you have used those devices, you really have no idea what shortcomings they have when dealing with non-standard html. As a user of accessibility software, I assure you - they are nowhere near as good as IE or FF!
Hockey wrote:As long as my site renders and functions almost identically in FF and IE I'm happy...
Are you coding only for yourself, or for the public?
And even if it is just for you, don't you take pride in your work? You are selling raw lemons and calling them lemonade! Talk about bitter!
Getting your page to validate isn't that challenging overall, and frankly, its only the first step towards great page design. As a bonus, it generally gets you a better page rating too!
Hockey wrote:My HTML is clean and easy to understand and likely looks the same on any device - except for the times I might use complex JavaScript - but still...
The key is "Likely". Your perception and testing of how often it looks the same on "any" device is guaranteed to be limited far below what the public uses. You've probably never even *seen* a braille terminal. Did you know that Verizon Wireless has over 100 different HTML-ready phones in active use by customers? Have you tested your layout in all of them?
No. And you can't possibly expect to. Thats why you code to a standard, and if they dont display the standard correctly, guess what - its their issue to fix.
Hockey wrote:It's not like browsers are going to stop supporting deprecated tags, etc...there is just way too many web sites out there which require tags like center
There is a difference between continuing to support old tags, and allowing them to be used in new doctypes.
New authoring programs are removing those tags now. As time goes on, more and more sites will use xthml, and html-strict/compliant, and by doing so, they'll get more consistent rendering in browsers. Thats a win for them. Then they also get css, which reduces bandwidth.
All these little things add up, and eventually, the number of sites with non-standard html will be in the minority, and then browser manufacturers can (reasonably!) stop supporting tag soup.
Sites that don't use compliant html will have no excuse when they do. Whether its "soon" or not doesn't matter. It *will* happen one day, and when it does, you'll be in pain.
Hockey wrote:So I ask, whats the deal with compliance anyways, sure standards are nice, but in this case I say not justified

You need to ask the opposite question. Why shouldn't I validate?
If I validate I get:
- Easy programmability
- Guaranteed improved accessibility on mobile devices
- Guaranteed improved accessibility on assisted viewing technology
- Improved ratings in search engines
- Guaranteed support in browsers now and in the future
- Better sites for your portfolio (Resumes with sample sites w/ invalid html shows incompetence)
If you don't, you get none of the above, and you get to be lazy at the expense of potential readers for your site.
I'd call it a no-brainer!
Not to mention, if you have problems validating, I guarantee people on this forum will be happy to help you get there.