there is no good reason not to merge mine this.
there are two, and here they are:
https://blockchain.info/poolsif CURE mergemined with BTC, cexio and that unknown chunk of private hashing would control most of the curecoins, pumpanddump them into the ground for BTC like all the other mergemineables, and generally reduce Curecoin's value.
Making a conscious choice to point one's SHA at Curecoin to benefit and encourage folders instead of just amassing mBTC is what gives CURE part of its value. If all the SHA was already guaranteed to be done as part of a mergemine, miners would consider X Curecoins per Ghs and the prices of it on exchanges would reflect that, not the folding.
Also ASIC devices are superceding themselves so damn fast now and becoming pointless for mining BTC so rapidly that Curecoin may as well use that hashing for the blockchain, since scrypthashing it would be a waste of fold-worthy rigs.
The point of hashing isn't to provide coins for miners, the point of hashing is to secure the blockchain. You could drop it down to 5% of the coins and still retain a secure blockchain. Hell, you might even be able to simply convince some bitcoin pools to merge mine it for 0 coins and have them do it because it helps the coin.
That said, this problem pales in comparison to the premine problem. If you want to pay people for their service (and you should), the way to do it is split rewards like devcoin, not a gigantic premine.