There is no need to go into this deeply. The matter is yet simple and complicated at the same time.
Here is an example: if Bitcoin was to be renamed this second to xxxcoin, it would be way to damaging for the coin and it would eventually die instead of progress.
You have your answer. Darkcoin was pretty well known over the course of the year.
You're seriously trying to compare changing the name of something that has been established since 2008-2009 to something that is almost a year old. Further, Bitcoin having far more exposure, invested infrastructure and branding behind it? Please tell me this is not the basis of your argument... that's just silly. It would be far easier and productive trying to change the name now in Darkcoin than trying to change it years down the road.