My old friend Walt always used to tell me life is a comparison, I may be a slow learner however I finally understand his wisdom. Saying something is good or bad without a comparison is of little value. To generalize about a country has less value until I compare it to other countries.
I have never thought of Thailand as being the land of 1000 smiles; however, it may well be this in comparison to the rest of Asia. However, then again the Philippines may have 2000 smiles and Korea and Japan just a few, while Laos. Taiwan and Cambodia are at around 250.
I believe this 1000 smile thing may have came to be used around the time of the American Soldiers in Vietnam were taking furlough over to Pattaya, Thailand. I would guess the comparison at this time would have indicated Thailand as being immensely happier, and for sure, I would only give Vietnam today a 100-smile country status.