I didn't suggest that this kind of humour does anyone any harm - I simply pointed out the fact that many parents may not want their children to be exposed to it. The company involved obviously thought the same, otherwise they would have put the warning on the pack.
This kind of thing has nothing whatever to do with our appreciation of subtle humour - and in any case one person's opinion of what's subtle isn't necessarily another's. It has a good deal to do with the marketing policy of a business however, and it's for that company to decide what warnings are issued. It isn't the company taking responsibility for what children watch - as some of the people in the thread seem to think - it's about acting responsibly, and telling parents that there might be something in the video that they would rather their children didn't see. The parents make the decision, not the company.
Whether someone thinks that farting is funny or not is a matter of personal choice. My feeling is that it's hilarious when you're a ten year old, but then some people have a tendency to stay ten years old as far as their sense of humour goes.