It's just not Thai-style Muay Thai (i.e. what you'd see in Lumpini and Rajadamnern, etc.); in fact, it's quite Westernized MT in a sense. All the World Team USA people I've trained with throw full 360 roundhouses ALL THE TIME, love the cobra/superman punch, have atypical kick mechanics (like they ALWAYS take a small 45 degree step before the roundhouse -- not just the n00bs but even the long-time guys; their arm swings for momentum/counterbalancing on kicks are unusual; they lean their upper body DEEP into everything as if they weren't scared of getting swept; knee and foot trajectory is unlike anything I've ever seen from any Thai MT camps), they use a more typically Dutch rhythm (i.e. jab, cross, L hook, R round) than a Thai rhythm (i.e. jab, jab, cross, R round), and have way more upper body movement than is typical of Thai-style MT. Now, I understand that every camp has its own stylistic differences (i.e. techniques from Sinbi look different from techniques from Petyindee look different from techniques from Eminent Air, etc.), but they all have certain basic common characteristics that mark the style as Thai-style Muay Thai. When you look at World Team USA, there are enough departures from these norms that it makes their style stick out as different than what's the norm among Thai camps.
It's not surprising considering Kru Sam has no stadium experience and is a protege of "Master" Toddy (don't get me started about that guy haha), but unlike Toddy he doesn't hire trainers/pad men that DO have stadium experience and instead relies on his own crew to instruct. But then again, it's enough for his guys to be effective on the American Muay Thai scene considering how low level it is here compared to Thailand, France, Holland, and Japan.
I don't want to sound like I'm talking shit about World Team USA, because I have met some pleasant people from there, and I do like the fact that they teach Thai terminology and the ram muay there, but that's about all I can say about them. World Team USA, "Master" Toddy, and Chai Sirisute's schools are all that sort of typical "inauthentic" Muay Thai endemic to the United States, versus the authentic-style schools run by former Lumpini and Rajadmnern champs (and there's a fair number of them throughout the US, just gotta look hard enough for them).