I don't know why it is so hard yo accept for you guys that the Irish tradition is a melodic one that gets its impact from something else than harmony.

This is clear, obvious and accepted. I was merely trying to suggest why English music as played over the last 40 years has evolved in its own particular direction.

Of course Irish music doesn't lack polkas (though in my limited experience they don't dominate ITM sessions), but the whole 'No Reels' approach in England - especially the South as Dick says - revolved around polkas played at a particular pace. Some of us in the North put a lot of effort in to finding alternative approaches, but this style - driven by melodeons playing oom-pah style - is still very influential.