This doesn't seem right.  every minute 1 block is being mined.  1 block = 3.28 NKA.  In 1 hour you could get 60 blocks MAX ==> 196 NKA.  In one day you could get MAX of 4725.  That would be $1.94 a day MAX, but realistically, you would get 30% of that which equals 57 cents.  Not worth to mine this coin.   So it is cheaper to buy the coin then mine.  Even if you have the fastest mining equipment, the bottle neck is 1 block per minute.  
I agree with you in that if you do the math on a day to day mining basis you can't ROI this coin right now. I also agree with these other posters that are saying the coin stakes and can gain in value so in the long run that mining could pay off.
Now with all that being said I want to point out that there are current discussions to change the block reward on this coin. This is to address the point which you precisely made and past that to help encourage mining which will help secure the network.
Question is a bit of mathematics will need to be done in order to decide what the block reward should be changed to. Based on your quick math you arrived at .57 a day. If you're math is in the ball park I would say a block reward of 50 would start looking very good to a miner. An IncaKoin block reward of 50 would tweak your numbers to something more like $8.70 a day. I suppose whoever decides on what the new block reward is will also need to consider that as that change brings in more miners the difficulty level will go up so maybe the block reward would need to be more than 50.
If we have any experienced miners running around the place I'd love to hear your input on what you think would be a good block reward number to generate good interest in mining this coin  
 EDIT:
EDIT: One other thing I forgot to mention that does matter. This coin mines right from the wallet with just a cpu. This makes it very miner friendly for a newbie since you wouldn't have to setup and run mining software nor join a mining pool. The bar for mining this coin is very low and one doesn't need high dollar ASICS, video cards, advanced technical knowledge etc. etc.