As Party Gaming is in the top 100 capitalised London Stock Exchange companies (the FTSE 100) most Pension Funds (and all Tracker pension funds) have money in it. Thus the US government action just hit our pensions (a small amount but still). Added to the fact that it smacks of protectionism and most brits really dislike the American religious right and you have a big business story.
It was the no. 1 business item for a couple of days and the No.3 item on the main news on at least one occasion (BBC).
As for gambling or poker being hardwired into UK psyche I think that's probably not the case. The majority of UK citizens put money in the National Lottery and bet on the Grand National once/year. That's about it. We used to do the football pools but the Lottery sort of replaced that.
Certainly that was the case for me - the only 'game of chance' I play is online poker. I have been to the horse races twice in my life and a casino twice too (not for poker just as a night out). Poker is on late night TV on the satellite channels a bit but that's about all the exposure it gets.
Betting shops have been open for 40 years on every high street but are definitely not regarded as glamorous. The historic image is that they cater to 'lower class' losers. Not Vegas for sure.