University snobbery can, I think, stem from insecurities about wanting to be seen to be part of a particular economic, social or cultural group. It can also stem from a lack of self-awareness that we all, to some extent, live in our own socio-economic and regional bubbles and this can influence our exposure to different people and situations.
I remember a thread about U of Exeter v U of Southampton. Some emphatically announced the former was clearly more prestigious than the latter; when quizzed it was clear this was based on knowing lots of Exeter alumni but no Soton alumni; absence of exposure was assumed, without sound basis, to be a negative for Soton.
There has been others threads querying whether Lancaster U was somewhat 'regional' (inferred to be a negative) when, in reality, it is probably less regionally biased in terms of intake than, say, U of Bath. Just because somewhere is some distance from your home region does not make it bad.
I think there can also be cultural overlays. St Andrews and Durham 'present' in aesthetics as 'near substitutes' for Oxford and Cambridge and, for some, this can be an additional dimension.
None of this matters if it does not influence recruitment and progression and hopefully this is becoming less of an issue but something to guard against.