Too many coins spread the infrastructure too thin for all coins. Coins are heavily dependent on people keeping up the hash rate high and rising to support increased usage. When people pull out of litecoin because the next TardoCoin comes along it weakens that and causes some coins to start to fade out. It would help out of people did not release coins that really bring nothing new to the table but at this point I don't think there's any stopping it.
Doge coin is worth $900k usd now. It was created as a complete joke to actually mock Chinese pump and dump schemes and look what happened instead? People started buying it up and treating it like something real. That in itself, made it real. It just shows how desperate people that missed the train are to hope and prey they can get on an alt coin train instead.
In the end, I think Litecoin will die out. There can really only be one coin, only one can survive ultimately. Soon as this alt coin fad blows over it will just be Bitcoin left standing for the most part (unless someone really puts something captivating in to play). While Litecoin offers some interesting changes I don't think they are substantial enough to take over the space.
Litecoin ASIC's came out recently in China, imagine how easily they could 51% attack Litecoin with a few of those at this point if they wanted to just end it. Likely they're just milking it for profit but it just goes to show the potential instability.
That's my opinion.
While I agree with the clone dying out , there are a few who might survive.
Namecoin has a purpose , the .bit domains.
Prime coin , although it may turn worthless in term of price , it can survice as a hobby for searching prime numbers.
The rest , trash can.
Look at quark how it lost 50% of the fans and they went to doge.
This will happen to the doge also when they switch to LLamacoin.