Google sitemaps - why isn't there an "official" tool to create one?

I'm not a big fan of sitemaps. If I've built my linking structure correctly, the Googlebot should be able to find and index all my pages in a natural way. However, because I've been trained to jump through the Goops (Google hoops), I build a sitemap for many of my sites. I use an outside tool that sometimes does a good job and sometimes does not. It's a crapshoot that often ends with me doing more work than I should for a process that I question whether actually provides any useful benefit to me.

Why doesn't Google have it's own in-house "official" sitemap builder? An application written by Google engineers who understand the specification behind the sitemap and know the internal workings of the Googlebot that uses the sitemap to traverse websites. This tool could be incorporated into the webmaster tools and provide a way after verifying the site to create the sitemap with a simple click. Also incorporated into this could be an HTML validator that shows errors upfront before they hit the sitemap.

So why hasn't Google done this yet? It can't be a matter of dollars and cents - they have more money than God. Maybe it's a bean-counter thing with the accountants asking "how does this make us any money?". Whatever the reason, it's time for Google to step up and either build their own sitemap creation tool or admit that the sitemaps don't really mean all that much.