i think in North America/USA, the horn/SET culture, and the economic support for promoting it, has almost been a zero for decades, with few isolated exceptions. and no brick and mortar presence for horns. maybe the European energy for horns is taking root slowly here more recently, but still just spotty for any big commerce with horns.
reviewers follow the focus of the listeners to be relevant. what else can we expect?
i do appreciate those doing horns and hope it gets more prevalent. i'd like to explore them myself but not much opportunity. but don't blame reviewers. these things happen organically.
you can't compare hifi to cars, there are zero DIY cars due to the laws. and mostly horns in this country are vintage or DIY to some degree. car reviewers review vintage about as often as hifi reviewer review vintage. i've seen it, but rare.