Depends. Lord of the Rings, for instance, has a lot of weird names, especially for elves. I personally don't like hard to pronounce names, because it slows my reading down. It's like when authors add crazy tags to their dialogue. That said, LOTR isn't marketed to me. It's marketed to people who love high fantasy, and crazy names, and unique languages--people who enjoy taking the time to really absorb that stuff.

Granted, you said "indecipherable" names. LOTR names arguably could be deciphered if you took the time to pull the name apart. So perhaps what I said is moot.