There's a world of difference between "difficult to decipher" and "meaningless."
Also, the onus is sort of on you to support your assertion. Myself and anyone else here can explain to you how to derive value from the market depth charts (if they have experience in trading). You are the one telling the rest of us we're wrong with no supporting facts.
Well let's see...
#1. You have no idea market depth data is even true, not just for the already mentioned reasons, but because there's not a reason in the world to trust that the exchanges are sending your correct data.
#2. The market volume is very thin, the liquidity is terrible. That means you get little to no information from the market dept you do see, and then there's all the stuff you don't see, which are the actual orders moving the market.
#3. Take a quick look around the board. Look at all the threads complaining about marekt dept manipulation, weird movement running contrary to market depth, constant huge order cancelation, etc.
And just as an FYI, experienced retail traders don't trade market depth because they know it doesn't mean shit because it's too easily manipulated.
Again, you haven't explained why it's meaningless. Spreading FUD, which is what your first and third point are, isn't exactly what I'd call factual.
I never said I traded solely on market depth - and I don't think anyone else does either. Depth is just another data point, and a useful one at that when planning your next moves (and particularly useful for automated trading).
Your assertion that market volume is thin isn't exactly a factual statement - more of an opinion. Thin as compared to what? Other BTC markets? I beg to differ. Thin as compared to any other currency market that's existed for longer than a few months. Yes. But then hey, this market's only been really active for a few months, and certainly hasn't been traded on for 100's years like the ones you're likely comparing it to.
It's a nascent market, and one that I've been watching obsessively since I've been developing toolsets to assist in trading, and while I've seen evidence of market-making (and even market-making bots), I wouldn't call that market manipulation, which implies something much more insidious or fraudulent.
Also, you might want to check your facts a bit - the dark pool trading has been taken offline since MTgox came back from the hack attack.