A condemnation of all cheap tires based on one catastrophic failure seems extreme...

I agree that there looks like a lot of tread left on that tire... unless it was on a fixie with a patch worn off it or something else extreme... but I would definitely send info to the manufacturer so they could check it out. It could save other people some issues.

Out of curiosity, I'm curious if you managed to maintain control of the bike... was that tire on the front or rear when it let go? If it was on the front, I expect it would have been real hard to stay upright.

Also, did the rock have sharp edges?

EDIT: Never mind on the front/back question, I just noticed the cassette in the picture...