You are right @gooddream I also think it boils down to money but I also think Thailand as a sovereign nation has a right and responsibility to regulate it's tourism industry just like many other leading destinations in the world.
But considering the fact that backpackers have been traveling in large numbers to Thailand over the years past, I think it would be insensitive to literally "kick them out" by introducing unreasonable requirements. This is something the authorities must manage as a process rather than an event.
This could be by way of introducing some kind of a well thought through campaign aimed at educating all concerned parties.
However the truth is that many leading destinations are now pursuing sustainable tourism practices through new marketing strategies.
This is because the conservation of Thailand's and our fragile earth's resources is ultimately more important in the long run.