By not citing his reputable sources, Massimo conditions people to accept his claims without proof and/or requires them to spend more time than it would take him to identify the missing source. Either way, it has a corrosive effect. Saying “people can do their own research” is like saying “it doesn’t matter if it is true.”
Best practice is to always cite and provide hyperlink to reputable sources, in order to provide a stark contrast with those who post disinfo that has no reliable source.