I think you need to find a practice method that keeps you engaged, so it makes sense to me to work in songs that you want to play, even if it is just a few simple riffs.

I've seen first-hand different styles of practicing and learning. My older daughter took lessons for years. I would hear her practicing scales and chords and lots of strumming. One day, my son picked up her pink guitar and started noodling around on it. He was immediately hooked. He never practiced the fundamentals, at least not in the traditional way. He went straight to working out by ear the songs and solos he liked. Within a month he was better than his sister. Within three months he was cranking out Randy Rhoads, Bon Jovi and even some Hendrix. Not perfectly, but he was rocking. Annoyed the hell out of his sister, lol.

Then again, he now works in IT and she is the one that headlines a band and is making studio recordings.