As one might anticipate from my username, I've had my interactions with the idol community, so I'm not unfamiliar with the premise of an unwavering fan.
However, I think broadly speaking it is unfair to so strictly define fandom. In fact, I think under such a premise, I'd be reluctant to ever admit myself a fan of anything, as there's no telling what time may reveal.
For example, if someone is a fan of an artist, and one day learned that artist was committing atrocities, or otherwise presenting a different brand identity than they had in the past, I think it's reasonable to want to distance oneself from that person.
For PS fans, I think it's reasonable for them to have wholeheartedly admitted themselves a fan in the past, but grown distant from that feeling over time.