As noted in the article, there are MANY variations of H.264 and many of them are extremely efficient and provide MUCH MORE color data than PhotoJPEG or MJPEG.
The reason why most stock sites only accept limited codecs is because of a support issue with end users. For a short time, Pond5 accepted any codec you could stick in a .MOV container. But they kept having to convert the footage for users who didn't have ProRES or other codecs used. Once they offer the ability for "end users" to re-encode footage on the server before downloading, artists will FINALLY be free to upload better and more detailed footage.
Several variations of H.264 are definitely PREFERRED for better color. And in fact, the new 3D file standard uses two H.264 "channels" and many modern theaters with digital projectors receive previews, commercials, etc... in H.264.
And, as the article points out, the responsibility for license is the "end user", not the artist or the footage site. Although nobody is even talking about this except for some legal people. The patent owners know that if they actually enforced those types of agreements, the entire industry would move to another format and they'd lose millions.