I agree with you on a lot of points TBH.
You can do a lot of projects via Bluetooth, Adafruit (a biggie in Pi stuff) carries project descriptions using this too :
https://learn.adafruit.com/programmi...ndroid-tablets
I hate Blutooth - I've found deliberately stubbing my toes a lot to be more reliable than Bluetooth and I wish it would die as a technology, but thats my experience 
The Pi wasn't meant originally as a general education tool though, more a technical and geeky / hacking thing to kick-start kids to be interested in coding again, as today (for some reason) making some HTML is considered such a thing - see the intro videos on that aspect.
Kind of like us old 80s-90s hackers with home computers - plug it into a TV and hack away. I had a BBC Model B myself
which was ace - built in Basic for quick hacking, inline Assembler for more serious stuff, built in networking, serial and paralel hardware, the option of
second processors (multi core in the 1980s, with 6502s ?) and a 1,000 page
Advanced User Guide (PDF) for those wanting more.
That tapped my son is interested in hacking via a different route - gaming. His "computing" course has spent the time from September to December last year doing the basics - history of computing, basic binary, memory etc. He was turned off and pondered dropping it altogether. Now they are hacking USB and WiFi connected game controllers and he is back interested in what he can do.
In other news, the PI now
has wheels.
