I know, and I appreciate all the armchair GMs who have expertise in this area. Fact is, without a crystal ball, it's impossible to know for sure which players will have a steady development, getting better every year, and which ones are at/close to their ceiling. No such thing as a sure thing, and hindsight makes everybody an expert.
All you can do is run the numbers, and then factor in how many teams will have money to spend, how many other FAs might be more desirable, who has needs, etc., etc., etc,...
Yeah, I get it, some fans think FOs should never get a call wrong, but hey are just human, same as you and me.
The funny thing to me, is if Derrick Favors had held out, he would have likely been maxed out as well. Then we'd have a fan base complaining that DL should have just maxed Haywood and should have known not to match Favors, because these people who don't own crystal balls should still have a way to get everything right.