I think that is a big reason kids aren't attracted too arrangers.

Also to get any satisfaction from playing arranger keyboards, one must know their chords well, play (or sing) melodies in their RH, and have good timing.

Kids have a great time with keyboards that they can create their own music (especially beats) on. I guess that's all possible with software...

I'm glad to hear that your students enjoy the piano though... That provides a great foundation for any direction that they may choice to go with their music.