While I do not disagree with a thing you said, I do somewhat agree with the OP. The salespeople DEFINITELY understate it. We did our research before we purchased (spent 5 years waffling on it before I made the walk). We are happy with our purchase. However, I did ask the salesperson this question when we purchased in 2010, and his answer to me was along the lines of "At 7 months out, you may not get your room, but you should always be able to find a room. Even if you want to come in a month, you should usually be able to find a room at some resort as long as you are not picky".
the reality has been far different. It actually was true for a short time back when we purchased. However, I have noticed in recent years it's been near impossible unless you are 10 months out in your home resort to find a room. forget 7 months, you need to be booking at midnight. You can't get ANY rooms ANYWHERE.
Do I blame Disney? No. Did they do anything illegal, underhanded or unethical? No. Could the salespeople be more upfront and honest? Sure. Would they? No - cause they are after a sale, not a happy customer.
So there is some truth behind the OP's frustration. My wife and I are going in November. We booked 6 months out. We found one resort - just one. Not our first choice of weeks or hotels, but we did find an option as long as we were flexible. I would like to get back to where I can plan 3 months out as long as I am willing to be flexible on the dates (I want to go for 5 days, but I don't care about WHICH 5 days). Problem is that lately there are only 1 or 2 days; and I can't justify flying for 1 day. Will that happen? I don't know. However, I would like it cause sometimes you are just having a hard year and you need a little Disney.