I'm pretty sure we all welcome constructive criticism here :) If you want examples of HTML5 evolving beyond "simple demo" state, http://www.chromeexperiments.com/ is filled with examples that range from "complex demo" to "modern flash game" to "I can't believe its not OpenGL!". http://www.pirateslovedaisies.com/ is a pretty legit HTML5 tower defense game. I'm sure you've noticed Angry Birds in the Chrome app store. Game engine-wise, Impact and Akihabara are both proven for quality pixel art games. While there's no Kongregrate for HTML5 (yet), professional quality HTML5 games definitely already exist, and if you seriously want to see solo devs putting out quality work, you'll find it.

It -seems- like your beef's not actually with the state of HTML5, but with what you're seeing submitted to this site. Which I guess is fine, but more focused criticism would be a more better way to help push everyone forward.

Personally, I just like seeing people make things :) Or I'm just reaaaally laissez-faire.