To the OP: I've noticed this with a lot of people (no matter where they're from, British people included) who go to a foreign country and then say offensive things about the country and then get surprised when they don't get on with the locals.
This can be Brits going to Spain and saying that Spanish people look hairy and ugly or Polish people coming to Britain for work and then saying how **** Britain is. How would you feel if British people came to Poland because they were looking for work but just spent their time saying how Polish people are ugly? I doubt they'd get very far. You're lucky that in Britain, people are very apologetic and critical about their country and don't get too offended by criticism. But this is a simple lesson in interculturality: if you want to get on with people in a country, don't spend your time criticising the country and the people. I know a lot of Polish people who are vehemently anti-British well what the **** are they doing here then?
As for the original question: Polish girls are attractive but in general, Hungarians or Czechs have a much better reputation. British girls are a huge mix (you'll find that British people who can claim that all their grandparents or great grandparents were British are barely a majority) unlike Eastern Europeans. I've travelled a bit and the idea that British girls are less attractive is a load of rubbish. Really. There are just as many good-looking girls in Britain than most countries. I find it pathetic when people just rely on stereotypes and some 3-week trip to Majorca, and watching TV to make their judgement on how good-looking foreign people are.
Yes, Polish girls are attractive but I almost find it creepy how Polish guys go on about Polish girls. It's borderline incestuous, a bit like how someone would go on about how his cousins are the best looking girls in the world. I have some good Polish friends and they'll point to a Polish girl and go on about how beautiful she is and I'll think "Yes, she's alright but there are about 500 better looking girls in a radius of 100 yards". Polish people also seem to be able to tell when someone has Polish blood.
British people just aren't that hung up about dating someone with the same ethnic origin than themselves. They'll happily go out with someone totally different.