Here's an article which finally says things I had only dared to whisper about.

Thailand:  Where are the Russian tourists? E Turbo Global tourist industry News Increased numbers of tourists does not mirror increased revenue.  In fact it's doing the opposite.  Large volumes of package tourists generally don't have the ability to be extravagant spenders.  Package tours tend to be a once in a lifetime event.  Most of their available cash went into paying for the tour package.  Tips are far and few in between.  Tour agencies arranging tour packages tend to get volume discounts, translating to less money but more work and wear and tear for businesses catering to these tours.   There's more money to be made from "people of means." They tend to expect more personal service and are willing to pay for it.  I can speak from experience having worked as a bellhop in two hotels and a country club.  I also worked as assistant manager for a hotel meeting and convention service.  I have worked around and served a few movie stars.  Even was within a few feet of a president. Early 1960's                     Elvis slept there

Thailand Tourism