Some people prefer to have that structure when learning something new, especially when they are so new that they don't really even know what they should be practicing in the first place. Am I supposed to practice chords first or am I supposed to practice scales first kind of thing. You wind up just kind of noodling around for 20 minutes and then get frustrated because you aren't really getting anywhere.
What I have found to be helpful is to go to the beginner lessons, go the practice for beginners tab at the bottom and do the Guided Practice Routine for Beginners taught by Lisa McCormick. You don't have to do it in order but I like to do the warmups and then pick a couple of the chord changing lessons to focus on for an hour.
It's not glamorous but it is fundamental and I have seen a huge difference in my progress since I now have some kind of guided focus.
Once I can't stand to do another exercise, then I look through the songs for beginners list and find something there to work on.
I'm probably a little different than a lot of players, unlike GT Staff, my motivation isn't so much to be able to play songs, but to learn a skill and get satisfaction from doing it well. On the flip side though, learning songs will help develop those skills and it is a lot more enjoyable than just doing exercises.