> motivated reasoning
You have things backwards. I agree with the hoaxers' motivation, and I assume that what they were trying to prove is presumably true. But their experiment didn't actually support those conclusions.
> What method of experimentation are you proposing ..
Lots of methodologies are valid, but if the whole thing is presented as science then the conclusions need to be consistent with the methodology used!
In the hoaxers' writeup, they said they submitted a bunch of absurd papers, but they all got rejected, so they gradually toned things down bit by bit until some of them got accepted. That's fine, insofar as it goes, but you cannot then turn around and claim to have proved that the journals will will publish absurd papers, which is what the authors did. You can't call a result significant if your methodology is to gradually lower the bar for "significant" until you get the result you wanted!
What the hoax actually proved was that the authors could publish a paper that they considered absurd, but which the journal considered fine. Which is neat - but isn't that already true of the regular papers these journals normally publish? Then what in the world did the hoax accomplish?
> The hoax proved that you do not need more than a couple weeks of training to become a published author in these journals
I don't think the authors claimed anything like that, where are you getting that? Their thesis was just that the content of the papers was absurd, not the times or credentials involved.