I think pitting one against the other isn’t helpful (and ‘modernisation’ as a myth has been around in various forms as long as the state so it’s hard to see that as a specifically ‘neoliberal’ or Celtic Tiger phenomenon).
Clearly there are pockets of radicalism in rural and urban areas. Talking to Brian Hanley over the years it’s clear the former have often been forgotten about or wiped out of history, but they most certainly existed, and it’s not difficult to see the current SF vote (however inchoate) as in part representing that (and another less happy example might be the ‘Spring Tide’ where LP TDs cropped up across a range of places).
But let’s be honest, these are only pockets in both places as we can tell even by that fairly blunt and unreliable instrument the CAHWT campaign itself. There’s beena broader deradicalisation over the last number of years everywhere.