Silk road may have impacted the price one way or another, but for me, the major reason why the price isn't doing pretty good is since the Gox incident. Too many people had been in doubt of bitcoin because of that event. Also take into consideration that there are traders who constantly play with the markets every single day.
I wonder why is it too much of a big deal for people to see bitcoin's association with Silk Road when in fact fiat is more heavily used in illegal activities.
The problem with Gox was that an inside bot pumped the price.
I think silk road added value to the coins, for sure, and this created a bubble in the first exchangers that were opened (some are now closed and some owners in prison for selling the coins for people who wanted to buy drugs).