Maybe i've been lucky, but in all honesty i've never seen any evidence of the 'supposed' blazer brigade mentality in any of the cross country leagues that i've ever participated in (M/cr and Distict, Red Rose, SEL, Mid Lancs)
I've just seen loads of hard working volunteers and officials (many of whom have been very successful runners themselves) giving up their Saturdays in all sorts of horrible weather to mark out courses and officiate.
Similarly from my experiences non affiliated runners, have and still do get a run if they turn up at any of these leagues.