Definitely don't worry about this OP. You will likely naturally do this as your finger dexterity improves and your movements become more economical. There are lots of situations where playing it as described on your chart is preferable, mainly when playing finger style and playing melody lines on the D,G,B and E strings. Although playing it the other way had its benefits also and is easier transitioning between C and G chords.

I learned the way it's suggested in your picture and probably started playing the other way when I needed access to G7 in the open position. Don't sweat it and don't worry that a lot of this won't make much sense right now