I mean that is pretty much what happened. of course the tribes fought against each other and everything wasn't amazing, but the arrival of the europeans absolutely destroyed the native peoples of the americas. that can't be in question. Disease and forced labor took a serious toll on the native populations, not to mention the loss of land. If you are interested in a first hand account of these atrocities I recommend reading Bartolome de las Casas (he was a near contemporary of Columbus and has secondhand accounts of 1492, plus his 1st hand accounts of the new world from the early 16th century).

Is it overly simplistic to say those atrocities directly lead to where Guatemala is today? of course, but discounting those factors is also a disservice.