> And "whether you are able to avoid injury or not" while trying to train up to that goal in the time period suggested depends on so many factors, like body type and genetics.
Not so. You get injured when you exceed your body's ability to sustain the load. You have to be aware of those limitations and work actively on building the ability to exceed them. In weight-lifting that means 1) proper form and 2) knowing when to stop. The former is easier to attain than the latter, but if you can do both, then you can avoid injuring yourself while still making gains.
> "Anyone who has experienced X must recognize the simple effectiveness of X" pretty much defines being a zealot for X.
That's ridiculous. I've experienced driving a manual transmission and recognize the simplicity of the system and that it gives you a better connection to your engine than an automatic does. Even so, I drive an automatic. If I had a sports car, I'd want a manual, but not for my primary vehicle.
I've done many, many things to keep in shape over the years. Starting Strength is great, but it's by no means the only or even best way to do that. That would imply perfection, which doesn't exist. What it is is effective at doing what it sets out to do. Which many other approaches and plans don't have.
What's great about SS is that you don't have to throw your whole life into it to experience gains. Just follow the program and you'll get stronger. If you didn't get stronger you weren't following the program. Many of the things I've tried didn't have this property. I took dance classes for a year before I realized I either needed to be rich enough to afford a private tutor or to have been dancing since I was eight to really get it right, and if I'm not getting it right, there are better ways to accomplish fitness goals.