Merriam-Webster Boners - #1: "Hispanic"

A few years ago, i wrote to Merriam-Webster about their definition of "Hispanic" in the Collegiate. The current edition was the 10th, published in 1993. The full definition, leaving out only etymology and pronunciation, was:
- adjective (circa 1889) : of, relating to, or being a person of Latin American descent living in the U.S.; especially: one of Cuban, Mexican, or Puerto Rican origin - Hispanic (noun) - Hispanicism (noun) - Hispanicist (noun) - Hispanicize (transitive verb)

This seemed very incomplete to me, as i had always used and understood the word also to mean "of, relating to, or being" Spanish speaking or descended Latin Americans in general (not only those living in the U.S.), and Spanish people, culture, history, literature, etc. There were Hispanic explorers. There's the Hispanic world. There are Hispanic countries, Hispanic studies... The list goes on...

I asked numerous people what they thought and not one disagreed with me. I checked many other dictionaries, including numerous recent ones. They invariably had a sense relating to Spain, usually one to Spain and Portugal, newer editions to Latin America, and a few to "living in the U.S." I even checked older Collegiates. Their 9th edition (1983) definition, in full, is as follows:
- adj (1584) : of or relating to the people, speech, or culture of Spain, Spain and Portugal, or Latin America - Hispanic n - Hispanicism n - Hispanicist n - Hispanicize vt
What ?! They removed* this and replaced it with a sense referring *only to persons of Latin American descent living in the U.S. ? Even if the older senses are in decline, they've long been in use and are found in literature. What was a young student to think if s/he read something about an Hispanic explorer and looked the word up in the Collegiate (or any of M-W's smaller and school dictionaries, as it turns out) ?
So i described all this to them, including my personal experience of the word, and sent several pages of representative citations i'd gathered from the internet, from all levels of speakers/writers, categorized by sense. Book titles, college courses... the evidence was overwhelming. By the time i was done, i was convinced my case was not even debatable. They had made a mistake and needed to correct it in their next edition.
Of course i couldn't have been the first to point this out to them. Surely they'd tell me they were aware of it and planned to fix it. But a few weeks later, i received an astonishing and bewildering reply from a PhD at Merriam. I wish i could find it now to refer to. It was a rambling, incoherent, rationalized defense which beat all around the bush and offered no cogent reason for removing the older sense.

When the 11th edition came out in 2003, it was about the first thing i checked: No change.
On the basis of this and some other experiences i've had with Merriam-Webster, i suspect they were protecting their reputation, strange as it may sound. They were trapped. They could not reintroduce the older sense without acknowledging a mistake on this conspicuous word. They had to let it ride and wait for the old sense to (presumably) die out eventually and hope that the removal would later be seen as forward-thinking.
Or has anyone a more plausible explanation ?
ER Lyon