The average age of DC and Marvel comic readers is still in their teens to age 34, despite the generational shift towards Manga.
The confusion comes in because comics are intergenerational, old fans keep coming back because comics are a great and healthy form of escapism, and because the comic industry was at its peak some decades back.
The Hal gap is a result of the parallax years when Kyle became popular alongside John Stewart in the JLA cartoon.
Hal fans consist of old fans and younger fans who grew up reading him or watching him in multimedia after rebirth from 2005 onwards.
What's different now is Hal's popularity isn't as monolithic as it was because he's largely been excluded from the JLA, and there are other GL's getting exposure in comics and multimedia (Jessica, Guy, John ect)