This is a good point, and worth repeating :)
I can see it both ways. Horse owners who want the freedom to do what they want, when they want with their purchase and the registries who are trying to maintain the integrity of what really amounts to a historical database of pedigree information. What would our 5 generation pedigrees look like if the trend was to freely change the horses registered name? Horses get passed around - if each owner wanted to put their own spin on their name - how do we accurately identify that horse and all phases of their identity on a pedigree? I think that is part of the hesitation on the part of the registries as well.