Unnecessarily long equipment loans to reviewers, and reviews potentially tainted by advertising revenue breed skepticism, in my opinion. While I would love to believe that all reviews are perfectly immune to these influences, my cynicism leads me astray of putting faith in them.
I recall when TAS and Stereophile went from being ad-free to acceptance of advertising. As I recall, HP claimed to have distanced himself from the TAS advertising coordinator, and thus was allegedly unaware of which companies were placing ads until seeing the published issue. I continued to subscribe for many years after advertising began, as it was pre-internet and few other sources of information existed on audiophile equipment and recordings.
Honestly, I felt greater trust in the reviews when advertising didn't exist in these publications, but am realistic enough to know that it will never happen again. But for a day, I'd bring back that 'closer to purist' time in audiophile publication