Order books mean nothing in crypto past the 5 minute time frame. They are easily (and often) manipulated by whales by putting up huge 'walls' to scare the price in the direction they want while executing the real orders in the opposite direction, scaling in and out of a P&D scheme.
Focus on the fundamentals. While I think Steem has potential I think that drawing rewards from market capitalisation alone can undo the whole project. Its just not sustainable to keep creating value for curators and posters out of thin air. The lack of advertising or other revenue sources may bite Steem in the ass hard.
While in a trading mindset avoid starry eyed idealism, force yourself to view both the best outcome and the worst case scenario. But if you believe in the project there is no harm contributing what you can spare, but that will be a donation, not an investment.
I agree, the sum of order books is a terrible metric.
You see, 10 million Steem (80% of all the bids) are placed at a price of 1 satoshi, which is never going to be reached.
A market depth graph which takes into account the current price range makes more sense, but even then I would not call that a reliable indicator.