I also question whether traditional academic distance may not often be as lazy, as simple-minded, as the kind of "vulgar aca-fandom" you are critiquing. It seems to me that it often comes from a refusal to engage with texts and the people who consume them. It often starts from an easy dismissal of the value of the work, a disdain for its fans and creators, and a desire to signal one's distance from anything commercial or popular. It often does not ask the kinds of hard questions you are claiming for the virtue of skepticism.
For me, then, there is no special virtue from either starting place -- only the need to be honest about where you are starting from and your own stakes in the analytic process and to be unsettled and multivalient in constantly questioning the texts in which you are engaged. To me, this represents the virtues of the best fan criticism and it represents the virtues of the best outsider criticism.