Here's another way to approach this discussion that I think can be fruitful. Let's ask:
"Why are peoples in the modern world so drawn to ancient Idealism?"
My short answer is that they feel like the modern world (which they relate to particle physics) is missing a heart, an substantive, meaningful context for a person within a rapidly changing world of symbols and technology. Epicurus' moral take on atomism, I think, provides a bridge between particle physics over what many perceive (ironically) as nihilism.
We predominantly find Therevada and Mahayana forms of Buddhism within the cultures in which they developed. Removed from this context (for me in America), "Buddhism" becomes a sort of "Eclectic, Pseudo-Religious, Psycho-therapeutic, mental compliment to the de-contextualized physical analogue of Hindu Yoga".
What I think we'll find is that the measurably beneficial practices that have developed within the Buddhist tradition are compatible with Epicurean ethics, in general. Any scientific findings from competing traditions that have a physiological basis and a measurably-positive impact are coherent with atomism, materialism, and the pleasure principle.
Therein, the parts of "Buddhism" that a lot of Americans like are really just secular practices, in the same way that Yoga has become a secular practice for non-Yogis. And a lot of American "Buddhists" are just non-religious.