The other problem with talking about "the fan base" is that it almost always leads to talk of "true fans" and "real fans" and other such gatekeeping, often accompanied by a dismissive, even sometimes contemptuous attitude toward new fans, casual fans, the general audience, "normies," "mundanes," "the masses," etc.
"All true fans know that . . . ."
Which, of course, usually translates to "My opinions matter more than those of those OTHER folks because they're not 'real' fans."
(Says the lifelong Trekkie who has been informed, on more than one occasion, that "real" fans call themselves Trekkers. Sometimes by folks who weren't even born when I was watching TOS during its original run on NBC back in the day.

)