No, you're not missing anything. Admittedly, the suggestion feature could use some work. That is why there are a lot of pre-configured schedules included with the software.
The suggestion feature works mainly on a principal that once the blinds reach a particular threshold, the tournament will likely end soon. It then moves the blinds up at a linear rate over the period of time the user would like the tournament to last. I'm sure there's a little more logic to it in there, but I haven't really looked at that feature in some time.
Many people like the first few rounds to go up at a slower pace, and then accelerate more towards the end. Something closer to an exponential curve. This would allow a sizable amount of players to remain in the tournament for a good while, then start forcing people to make tougher decisions later in the tournament. Of course, it's all up to you.
I would take some of the included blinds schedules as examples, and see what others around here suggest. Real-life use will always trump what a blinds calculator can come up with.