This is necessary because too many people are using the tools for free and we're not meeting our revenue goals."
It's not that I am lazy, incompetent or not creative, I just like using the full toolset. Giving people a taste of that tool set in a free trial will have people coming back for more.
Most users are hobby game designers and kids and having a free version with limited events is what they need to learn and after they get some experience they buy a licensed version.
15 days is not enough time for most people to even get a first game completed and they will give up when the time on the version runs out and go look elsewhere.
If you want families and other features in the licensed version then buy a licensed version and you can show your students on your version what can be done with a licensed version.
Gamesalad and some other engines are trying to lock people into a purchase or subscription and it will backfire in my opinion.