Whatever the original intentions were are irrelevant now, and the hobby is different from what it was even a couple of years ago. I assume it will change again, which can be seen by the regularity of this topic.
The greenest of newbies has more insight and access to information keeping SPS than those did in the past. They have the benefit of the success of those people early in the hobby. What is "boring" or "common" today could have easily been the most exotic colored piece they have seen. Keep that in mind when asking "Why is this an LE?'.
The explosive growth of the hobby, the emergence of the industry and the money that can be made, has tweaked our perception and understanding of an LE.
Ask yourself, why does it matter to you? What are your motivations for buying, or not, these "named" pieces? Does everyone have your same point of view or motivations? These questions will help you start to realize, there is more to the issue.
Most will agree a "named" piece is different because of some point in its captivity it has transcended from being just an Acropora Echinata to a part of the culture, obtaining an individual identity that sets it apart from the rest of the "Acropora Echinata" out there. This goes above and beyond whatever the "unique"......I repeat "unique", traits that set it apart.
One of the things I enjoy the most is hearing about the stories about how this piece was discovered, or how it was thought to be lost and resurfaced, etc.
Its these things that differentiate pieces from even the same specie, that are often times overlooked and need to be considered as well.
Big topic, lots of things to consider