Yes but that's not a use for the COINS.
Mathematicians may run primecoin for the fun of it, or for scientific value.
Miner, traders, and normal people are going to stop running it at some time if there's never any use for the coins it generates.
Same holds true for Litecoin, I see hardly any site accepting Litecoin. But does that mean people stop mining Litecoin? The opposite is true.
This whole cryptocoin thing is currently created and supported by miners-speculators, mostly.
The question of price, which this thread is about, is not determined by utility (the usefulness of the coin) but rather, the economical movements.