Indeed, because they do work quite well. I have a CD case sized panel and I charge my phone with it in normal daylight. It pumps out about 500ma in bright sun so takes about 2 hours to charge my G1. For better utility these are cool too http://cgi.ebay.co.uk/Solar-Power-Battery-Charger-for-iPod-N...
I've bought two solar chargers in the past, and neither worked on my iPhone, although they did work on other phones. The way I understand it, the 300-500mA output of this and other compact solar devices just doesn't cut the mustard with the iPhones, which have a current requirement above standard USB specs. If I'm wrong, and/or you know of a pocket-sized solar charger that'll do the trick, do let me know.
For one thing, why doesn't he turn the device over and see what its name is, rather than calling it "Apple Tablet"?
Solar pad charger, that doesn't really work? Very unlike Apple.