Cause and effect.
I would venture that most 'speculative' stories are by their nature, going to be 'negative' in some shape or form. Cage rattling stories sell; lovey dovey 'everything is tickety-boo' stories don't.
Take yesterday for example. Two stories about Koeman... One from the Liverpool Echo linking Koeman with the Everton job (according to a mystery 'source') and another article penned by Simon Peach where VvD says he's convinced Koeman with stay at Saints.
I wonder which one of those stories made the back pages this morning...?
Its human nature to disbelieve negative stories that appear to hold no tangible substance. A bit like when the media publish a negative story about Jeremy Corbyn, for example, some people's natural reaction is to automatically disbelieve it....