I know it's a bit utopian, but ultimately it would be much better if retailers held on to their DRK (or BTC). If not, you have a system in which people spend fiat or BTC to buy DRK probably hoping that it will increase in value, or in the worst case scenario, not fall. The you have retailers trying to attract customers who want to spend DRK, not necessarily because they believe in it but because they see an opportunity to make money. That would be ok, but when they trade directly for fiat the price goes down a little and the more success these retailers have, the more downward pressure there is on the price.
It's not utopian - just ahead of our time. Adoption takes time and this can be accelerated (or not) but it will still take time. BTC is on for 5 years and its adoption is near zero in real life terms. Paypal wasn't widely adopted for quite a few years too.
In the future when Darkcoin is more established, it would be great to see a company like Coinbase springing up which only offers DARK>Fiat conversion. Then we could really move beyond BTC fluctuations.
I don't know if it's really possible to escape them due to arbitrage opportunities in the DRK/fiat vs DRK/BTC markets. If they deviate a few % between each other then traders will fill that vacuum by moving DRKs around vs fiat or BTC, from the cheapest pair to the most expensive pair. So, naturally, these two prices will be very closely aligned.
LTC has LTC/fiat pair in a few exchanges yet it goes up and down due to the same mechanism.