Oh you can KO people, just more likely to break your hands. Thai fighters utilize kicks far more and I read that they don't fight hard in the first round, start to pick up in the latter rounds. Reason is that they are all poor and they know they need to do this to provide for their family. They're not looking to hurt or maim their opponents where they end up in the hospital. So yes it doesn't seem like they go 100% until the latter rounds...even at that it may be 80%. Again this is my observation and from an old article I read. Anybody who's trained in Thailand can maybe elaborate more on this.
It's very honourable not to say that they won't try to take your head off, but it's certainly not the same as everywhere else. They have a sense of tradition and honour.
That's totally not true!
But their training is all dependent on NATURE rather than machines, just check their trainings you'll see their body's take hurt more than UFC fighters does in an OFFICIAL match!
And just for the answer to the subject:
Bare hands smashes faces and brakes bones, were using gloves makes you DISEY and that's what we call KO