Is radio quietness really an issue at millimeter wavelengths on the top of a mountain? The wavelength of every wireless device in my house is a couple of orders of magnitude longer. Not to mention all the ground level water vapor that would damp it out at those wavelengths. I expect the large amount of lightning at the Sierra Negra site causes far more problems.

That leaves cost… I guess it must be cheaper than building it in the US.

Do you have any objective proof for those assertions? You sound like a salesman.

Oh, and from the point of view of ops cost and sky transparency as well as INAOE partnership (the latter two you don’t get by putting it in Nebraska), Sierra Negra offers more value to science than any site in the US. Also, it happens to be more radio quiet than most places in the US. Gosh, those scientists actually use their noggins once in a while, don’t they? You’d think they’d listen to self-styled pundits on blog sites instead.

It was a mistake to locate that telescope in Mexico, assuming this is the agenda:

The LMT is a large radio telescope that astronomers hope to use to probe the early history of the universe and study clouds of gas and dust from which stars form, among other planned research projects.

A better location? the Moon’s far side, where the antenna[e] would be shielded from Earthly electromagnetic emissions.