Double, I don't disagree with you. Actually, only half of my problem with 10% is that it's sometimes too conservative. The other half is that it's sometimes too aggressive. I've seen people say "I was following the 10% rule, I was even increasing by only 7%, why did I get injured?" Following the "rule" gives them a false sense of security. They got injured because the right increase for them may have been 2% or maybe they needed to stop increasing for a while.
You're absolutely right. The most important thing is to just get out the door consistently. Do that, throw in a workout or two per week, add a few tune-up races and you'll do pretty well. The question becomes, when first building up or after a layoff, how do you build up to get to the point of doing that consistent volume? For some, 10% is unnecessarily restrictive. For others, it's too aggressive. As I always say, the key is to not let arbitrary rules get in the way but to instead listen to your body.