DASH can be copied. We, or someone like us can try again. Not only that, but modifications, whether we make them or others make them, are now possible.
That is my view when I am feeling optimistic. At other times, I feel the race will be very close and the outcome is uncertain. My chronic theme is that underestimating the strength/power of future pushback is dangerous, and that future-proofing is wise.
I was elated to see you are thinking of setting up a decentralized exchange. I've followed the progress of, say, B&C, but my perception is that they have become semi-centralized as they progress from vision to reality. Any interface with fiat will always be a choke-point, imho. I hope you solve it.