It's not bad at all. I rarely book 30 days, but I might book a few weeks ahead of time (for TSMM and 7D). I decided to see what was available in MK just for tonight and plenty was. I could just about pick times. (Did not get 7D for tonight but we can get on after Wishes easily. And we did get same day 7D on Memorial Day this year, after 4pm!)
We can pick up SM, BTMM any time, EE easy. As locals, we won't ever get the 60 option. 30 is plenty in advance. Many people coming to the parks don't even know about the FPs and book when they get there.
If you don't see what you need, keep playing with it, keep trying dates. Also, the Options it gives you, pick the closest one you like but you aren't stuck with that, you can change the times as needed (as long as its not sold out.)