IMO, after gox, all momentum in bitcoin was lost. The problem is that the general public who had been wading into bitcoin and which was curious about it, became scared. When you balance the risk the public sees with bitcoin vs. the benefit they get from owning it, the risk is too high. As a result, no new money is coming into bitcoin - it's that simple I think, and I believe it may never come back.
The price will simply grind down to a much lower level bc there simply aren't the needed buyers, and the miners who mine 3600 new bitcoin every day have to cover overhead and they will always be selling. When there are more sellers than buyers = lower price. (I think that major miners had been holding off selling after gox to keep the imagine of bitcoin up, and I think there were some major players who tried to prop up the price for a while for the same obvious reason). But the confidence in bitcoin is gone and it is not coming back except for the hard core bitcoiners (of which I had been one prior to gox's collapse).
That still doesn't explain why the recnet downward trend happens in late March, not early March.
Do you think the majority takes a full month to chow the MtGox fiasco and decided to quit now? This timing makes little sense to me.
You said miners caused it. If after MtGox everybody are holding or buyers/sellers reaches an equilibirum, and miners are causing disturbance, then the support should be the cost of power, because miners who are holding tends to refuse to recognize the lose. According to seriouscoin's recent post: "Buying a mining gear at current exchange rate, you will have very little chance to BREAK EVEN". So I doubt miners are asserting downward pressure. Besides, this "miners did it" execuse can be used any time to reason a fall, it is just too convenient to be true.
The current bear market is primarily a correction to November 2013's insane hype bubble. If you analyse the current wave of FUD you'll notice that most of the complaints about Bitcoin are akin to "I thought Bitcoin automatically gave me immortality and the abilitiy to travel through time".
Why the correciton doesn't dub with the MtGox fall, late Feb and early March? It should, IMHO. I consider that if a correction has to happen, it tends to do so at the bad news, and MtGox is a very bad one.