right but they do lock them down. As it says on the parent url, "Due to licensing restrictions, these [GApps] apps cannot come pre-installed with CyanogenMod and must be installed separately." Google heavily licenses GApps.
The incentive for them is to stop folks like Amazon installing Google Apps on their Android fork, and to encourage Chinese/3rd party/etc indie OEMs (the kind no-name tablets you see on eBay for $100) to establish a relationship with Google in return for then being able to supply GApps on their devices.
Holding the keys to GApps is what allows Google to give away the rest of the castle (Android) and still maintain control.
The incentive for them is to stop folks like Amazon installing Google Apps on their Android fork, and to encourage Chinese/3rd party/etc indie OEMs (the kind no-name tablets you see on eBay for $100) to establish a relationship with Google in return for then being able to supply GApps on their devices.
Holding the keys to GApps is what allows Google to give away the rest of the castle (Android) and still maintain control.