Prior to Monsatan's involvement, Snopes wasn't corrupted, to my knowledge.
I am unsure when it happened, but Monsatan could have been the factor that began the descent of it's founder into the hell of debauchery and fraud he has undertaken.
Due to it's previous counter propaganda role, Snopes may have been relatively financially unrewarding, and I expect his becoming a proselyte of TPTB might have been worthy of an entrant to the Cannes Film Festival, given his current trajectory.
From the very beginning, the founders of the site were staunch "democrats", and supporters of Clinton/Obama/etc. Even without financial ties, that alone is enough evidence of a lack of research and understanding of the real world for me.
I don't really ever recall a time when I thought snopes was reliable, but I can accept that they got worse and worse.