They will catch on eventually. Its unique codebase makes it a good hedge should flaws be found in the Bitcoin codebase. Should this scenario manifest itself all Bitcoin based coins (DRK/ASH) would be rendered useless as well.
The flaw of everything related to Bitcoin being highly political and subject to a thicket of conflicting entrenched interests can't be easily fixed. That's why, for example, they have been talking about the block size for years and are no closer to a solution.
People in the crypto world need to just get used to the idea that crypto markets never will be like more traditional markets. Bitcoin never will be like gold. Crypto currencies are going to be constantly upturned and replaced and capital will constantly be flowing all over the place. Bitcoin will come and go, and what ever replaces it will come and go, and so to with what ever replaces bitcoins replacement. The solution to the blockchain size problem is to not attempt to arrive at a consensus, it is to just let the fork happen and let people go their own way. Crypto currencies will never be a place for savers, they will be vehicles for transferring value and for dedicated and nimble speculators. Scripted blockchain based derivatives contracts will allow people to hedge against volatility for a fee if they are just simple users so the tumultuous nature of these markets wont necessarily need to deter mom and pop. If you want to save, buy a gold coin. When you want to move the value that that gold coin represents to the other side of the planet instantly, that is when you need crypto.
Yeah, the evolution over time will be interesting. I.e., for those cryptocurrencies that are actually currencies (bitcoin, litecoin, monero), I can see things just constantly getting replaced and upgraded. The in-betweens will be interesting for speculators, but it will really all depend on merchant and customer adoption.
"Oh, we don't accept bitcoin here because confirmations take too long, the network is centralized, and transactions are traceable. But we do accept monero"
and then
"Oh, we don't accept monero here because (insert some reason that is sure to exist eventually), but we do accept SuperMonero."
Yes, will be interesting to watch these things evolve.