Thailand is past it's prime and lost momentum. It's tired, dirty, lacking, and has lost the appeal it once had for tourists in most tourist areas...not to mention the low-quality tourists they attract.
There are new, different, cleaner and cheaper options elsewhere, and while Thailand will always do ok, it will never be what it once was.
Thailand can flip flop between opening up to the masses and claiming they only want quality tourists, but the fact is, they will take almost any tourist they can get.
It was a good ride, Thailand, and as much as I enjoy living here, the tourist gravy train is probably over...