Yes, it IS obvious, but what difference does that really make? On a day like today, for example, it was impossible to tell which trades were buys and which were sells. Probably many went off at fractional prices, but we can't see that.
My guess is that these people don't think of buying and selling the way we do. I suspect that they want to obtain a specific total price for a specific quantity of shares. The total wouldn't be precise, but it'd be a ballpark figure. So the MM filling the order does his best to keep the stock in a range in which he can fill his order for more or less the amount the client wants.
These guys aren't unrealistic. They want to make a profit and are disinclined to wait for pie in the sky. There're a lotta other opportunities out there.
