I think that line was being a bit cheeky. It seems to be excluded for the same reason JPEG2000 is: it's patent encumbered.
That really annoyed me. The blog post tries to do a lot to appear scientific and objective, then just tosses something out without testing due to personal opinion.
They also mention it’s not free. That would be ok. Just say your test is image quality of free image formats.
But that statement just undermined the trust I had in the author up to that point.