Yeah, all this is true. You really have to have the motivation to be able to learn it yourself, and a lot of tuning isnt straight out of the textbook, you have to get creative at times.
You either have it or you don't.
I taught myself how to tune, simply out of the fact that I wanted to. I always thought it was intriguing, I had a solid background mechanically, and wanted to do it for myself. So I spent hours and hours reading forums and experimenting with my own stuff. I still experiment and learn something new every day.
Also, like Matt says, I find that other tuners will answer questions for you (and vice versa) if you have a specific question or specific issue that you are encountering or can't understand. By intelligent conversation on specific subjects, a lot of good info can be learned on both ends. BUT You can't expect someone to hold your hand and walk you through it, you'll never get good like that. Don't expect to be taken seriously or actually become proficient by being spoon fed info every step of the way.
Tuning takes a lot of time and effort to get down properly. Don't expect you can sit through a class and you will know everything there is to know. For 99% of the people out there, in the long run it is a bit cheaper and more efficient to hire someone with experience to do the tuning.