Pete, I take onboard your comments about the visa system and acknowledge that there are some who abuse the system and overstay. However, the British government treating all genuine girlfriends as probable scammers does pose a difficult situation. It may be difficult for many men to make multiple trips to the RP to see their girlfriends/ fiancees prior to making a commitment to marry. If it was easier for the girlfriends to come over, spend time with their future life partner and, as you say, see British culture first then everyone can make a balanced judgement before getting married.
In my situation, although my lady and I had a very intense online and telephone relationship, we had only spent two holidays together in the RP before she came to the UK on a fiancee visa. And because the visa ran from the date of the interview and not from the date she left the Philippines, we had to get married within 5 months. It all felt very rushed and although we have no regrets, we'd have liked to have had more time visiting each other and getting to know each other before getting married. Let's be honest, it's a major culture change for the wife and we guys have to get used to the lady's ways. That's one reason for forums like these, to find out these things.
Surely if a sponsor provides a return ticket and some sort of guarantee then there should be no problem granting a girl a tourist visa.