True, my mistake.
I was confused between iTunes Radio and iTunes Match. What I meant to say originally, if I hadn't, is why don't they use all the "Genius Data" that's constantly syncing between my devices to improve the song selection in iTunes Radio.
Also, using iTunes Match only works so long as you have some type of connection. Any type of connection. Thinking it's a great way to free up space on a device is not probably what it's meant for. I learned that the first time I used air travel after thinking the service was great. After that I disabled it on my devices, upgraded a few times and ran into the same problem while on a train. Now iTunes Match is I'd disabled on everything except my "media mini" which has everything media based I own on it anyway.
Maybe it's great for some, but it got me twice while traveling for extended periods with absolutely NO media. Also, I have a ton of songs that are not matched that I imported from my CD's. So personally I couldn't say that I could listen to ALL of my songs using the service.
I still have the service. It just renewed on me last month I believe, but I don't use it for much. Luckily the cost is negligible.
If it works for you then great! :o)
You should have prepared better for your trip, by storing some of your music locally and turning match off.