I've been married to my Thai wife for 3.5 years. We dated for another 3.5 years before we got married. My Thai wife has a masters degree in one subject, and working on a master's in another subject. I only have a bachelor's degree, but my lack of education doesn't seem to have damaged the relationship too much.
So far, from my perspective, the marriage seems to be working OK.
We live in Europe. My wife has a couple dozen female Thai friends, who live in the same small city. All of them are married to westerners (variety of nationalities). Most have been married from 10 to 30 years. Some have been married so long,they have children who have graduated from European universities.
Earlier this week, we went to supper with a couple (European man and a Thai women) who have been married for around 7 years, and been living together in Thailand for about 25 or 30 years. Their relationship appears strong.
Who ever said Thai and falang marriages don't work, in making such a general statement, really hasn't a clue as to what they are talking about.
Now if the individual had stated falang and Thai Bar Girl marriages don't work, I might have given more credence to the statement.