Re: Not really their fault
I easily fit a Linux image in 16Gb on a micro SD card with more than enough room to spare, with chromium, a web server, custom daemons, and short instructional videos, yotta yotta yotta, operating in 'kiosk mode' on a Raspberry Pi. Set it up properly [and config the browser to only check for updates after 1000 years have passed] and you're all set! Well, you DO have to code it properly...
[and if you're worried about the GPL, you can try FreeBSD instead]