That writer spent a lot of time drawing inferences based on process concerns, but I'm not seeing any proof (or even allegation) that Snopes "has been known to make this shi- up as they go."
The proof of the pudding in any article, whether written by Snopes or anyone else, is whether the facts cited in it can be independently verified, and if they can, whether the stated conclusions logically follow from those facts.
As for the Daily Mail article that got him started on the subject, that too has come under criticism:
https://www.theguardian.com/media/2016/dec/23/why-is-mail-online-going-after-fact-checkers-snopes