I understand your want to have Silver Kayle and Judgement Kayle, but these are skins that mean something to players like me who remember staying up with their friends all night well into the school night years ago playing ranked matches in order to obtain Judgement kayle. It would also be unfair to those who spent money on the collector's edition box in order to receive Silver kayle. These skins are Riot's way of saying " Thank you for supporting us back when we were a small Indie company." I always get excited when i see another person in game with a Judgement Kayle or Silver Kayle or even a King Rammus skin, because i can have a nostalgia trip with that person about the days when LoL had absolutely terrible graphics, and more than it's fair share of bushes. I remember when red buff was a bunch of lizardmen and raptors were wraiths.
Asking for exclusive reward skins like these to be made public again would feel more of an insult to players like me who have been playing this game for this many years. It would almost be like asking Riot to give you the Legacy banner on an old skin because you happened to get it out of a box. I remember raking leaves for hours trying to scrape up enough money to buy Haunting Nocturne before it got locked up during the first harrowing event. Personally I WANT Riot to leave skins like these exclusive because it makes me feel like they appreciate the time i spent to obtain this skin and other Legacy skins when they were new and exciting.
Another thing to consider are other exclusive skins that may be much rarer in the future like the Prestige skins for the K.D.A. set or the prestige bloodmoon set. In like 3 or 4 years you will have people begging Riot to bring those skins back, and then everyone who spent the time to grind games for the 1000 coins or spent $200 to get the coins will feel cheated because now their skin they worked hard for now has no sentimental value attached to it.