While the diatonic scales are great things to have knowledge of I have to say that the kind of importance you are putting on them is blown way out of proportion. I mean if you wanna stick to classic rock or something ok sure that's great but I think you need to stray away from diatonic scales in order to get somewhere in other styles of music. jazz requires a bit more than diatonic scale theory. Blues favors chromatics. Classical music has never stuck to a diatonic pattern. Even metal doesn't stick entirely to the church modes. Sometimes you gotta get away from the diatonic scales and take a risk. I passed that about a year into playing. I couldn't imagine how bland music would be if everyone stuck to your formula.