Likely due to the lack of smileys indicating humor.
Of course the alternative is to endorse the project then be responsible for the consequences. I would find no humor in killing someone or having them burn down their home. If you find that funny, well, no further comment. I take injury or home loss very seriously.
I can EASILY see where someone would try that because it's presented in such a way that is plausible-sounding. IOW, there are a lot of people out there who don't know any better. Should we just keep them in the dark all in the name of humor?
Humor seems to be lost if someone has to cue you in on it.
I don't think the original post sounds plausible. If someone gets hurt doing this they probably shouldn't be allowed around electricity or sharp objects. Also I think that they would end up inevitably hurting themselves if they lacked the intellect of common sense safety. I found the post amusing. We can't sensor the net just because dumb people might hurt themselves. There would be no fun youtube videos either.