There are several reasons IMO:

• It's a very white sport

• It's a very expensive sport to play, which means that a lot of the people who can actually afford to play are from wealthy families

• People are getting poorer and thus less younger people are playing/watching hockey, meaning that there's probably a higher boomer ratio than other sports (case in point: hockey is no longer the top sport in Toronto because basketball has a much lower barrier of entry ᵃˡˢᵒ ᵇᵉᶜᵃᵘˢᵉ ᵗʰᵉ ᴿᵃᵖᵗᵒʳˢ ᵃʳᵉ ᵃᶜᵗᵘᵃˡˡʸ ᵍᵒᵒᵈ)

• It's historically stoked lots of xenophobia, especially during the red scare w/ the Soviet Red Army teams. A large number of hockey fans, especially older ones, haven't been able to let go of their "good ol' Canadian boy" prejudices, not helped by dinosaurs like Don Cherry

• Hockey, like most sports, is hyper militarized - constant bombardment of military propaganda during games

• Hockey players are conditioned to be reserved and conservative, in manner and dress - usually in opposition to the way athletes act in other sports. See how angry people get when a hockey player is too happy for scoring. Of course this has racist implications too, see Evander Kane in Winnipeg.

• Hockey is a violent sport that has fostered toxic masculinity mentalities for ages, especially since fighting and violent head collisions were pretty much unofficially allowed for most of its existence and any talk to the contrary was considered "soft" - which in turn also makes a lot of hockey players super homophobic (source: routinely heard slurs when I played)

• Hockey is the _only sport in some smaller Canadian towns and a lot of those towns tend to lean reactionary

• Edit: Someone else brought up a good point, hockey is a very "justice served" type sport that appeals to punitive justice crowds, e.g. if one of your players gets injured by a hit, fans are going to be calling for blood