Mexico all inclusive vs Thailand. Anyone that has been to these two places would have to agree that tipping directly correlates to the quality of service. This is why I'm going back to Mexico for the 9th time in 4 years.
Tipping in Thailand is not much of a thing. The service greatly suffers from this. If you do go into a 5-star hotel in the city they tend to attract a crowd that expects tips. This is where you can find really good service. The people were always pleasant, just not very motivated to serve you.
Everywhere I've been in Mexico the service has been top notch. In all inclusives you are still expected to tip the people.