I agree with you that people will find certain sports unappealing for whatever reason. However, a portion of the people, who dislike the sport, may be derived from how an organization runs the sport or the rules an organization decides to implement for a sport.

For example I no longer watch baseball and NASCAR anymore because of certain decisions made by the respective organizations. I lost interest in baseball when MLB decided that the Astros, a historically NL team, must now switch to the AL because MLB wanted both leagues to be balanced in the number of teams. For me I lost interest in NASCAR when it decided that races will be broken up into segments (which is a common practice at local tracks) and that all the laps ran under caution would count towards the next segment. I used to be a huge NASCAR fan in part because I familial connections to the sport (my somewhat distant cousin is married to Kyle Petty and my late uncle was Ricky Rudd's lawyer).

My point is that a ceiling to any sport may in part be due in part to decisions made by organizations trying to promote the sport. It may also be due to the lack of understanding/knowledge a person has about the sport. So I don't see that ceiling as being a hard ceiling even if you are looking at a particular age group.