You can't judge normal Thai women by what you meet in tourist areas like Pattaya, etc. That's not a fair assessment. The majority of girls you meet in a place like Pattaya or Bangkok, who work in bars or massage shops, are single mothers desperately trying to eke out a living. Thai women are generally very loyal to their partners, and it's the men who start messing around and leaving them with children and no support. Once a woman is single with children, she has limited choices to support herself. Apart from having young children to look after, she also has family relying on her. It's a very hard life.
There are lots of non-sex workers looking for good partners. Just do the research. If you're looking for a good woman, you can't do much better than Thai.