The main reasoning they have for this is to have a clone for a major producer under their own control (hint: Cloning a horse is rather expensive, really...quarter of a million) or if one were to die due to old age or accident to have a "backup" of something like Rocking Rodder or King so they can continue showing and breeding a prize stallion.
Honestly, I'd love to have a "backup" of my $500 gem (She took the first-ever Arabian Horse Association Youth Nationals in the Half-Arabian division and is 2012's Reserve National Champion- I bought her as a minimum bid at one of the big Arabian Horse auctions... Oh, little did they know about her... :-D )- but I can't see where it's a monopoly to exclude them like the Judge and the Jury saw it. The registry's purpose is to verify and certify parentage (A clone has but one "parent"- the animal being cloned) and to manage things like competitions. The rules state a purebred foal/horse is one of two purebred parents, a dam and a sire, a mare and a stallion. A clone doesn't HAVE that. Genetically, it's a purebred, so long as you're not genesplicing it as well- and how do you prove that one out?
There's a mess there and it's not something where the decision is a good one. Worse, the suit was brought by a group of individuals that are really solely doing it for financial gains- they're involved with one of the main companies doing the horse cloning. It wasn't a case of someone wanting to clone a Rocking Rodder...it was a case of the bunch doing the cloning to open the floodgates for their business.