The two-position system really came about some 15 or so years ago. I had somehow wound up at an ex-girlfriend's band rehearsal and was chatting with the guitarist, a really tasteful player, and all-round nice guy. At the time I remember being heavily entrenched in 3-note per string (3NPS) scales and a general excess of technique over musicality. This guy, on the other hand, always seemed to play the right thing in the right place, just simple melodic stuff that would blow you away. I took the opportunity to ask him about his approach to scales. Incidentally, we had both been through the same music college at different times and had pretty much the same teachers.
He obligingly explained to me that the way he saw it, you had the option of playing a scale or a lick in various places on the fretboard using a one-octave shape. As he played he kept it all within one octave but there were no obvious patterns. Then it suddenly dawned on me...
The way you learn a scale must be consist with what you want to use the scale for, in other words, the actual physical process of learning a scale is a means to an end, not the end in itself!
So off I went with my new found perspective on all things scale related and turned the thing on its head. What did I actually want to able to do with scales? What were my goals? I would really encourage anyone to look at scales from this perspective then work your way back to the actual method by which you're going to achieve your scale goals. For me it was access to the scale, melodic control and the reduction of thinking time. Once I realized that 3NPS scales did not suit my purpose, the 2-pattern system was born. I began to explore it, refine it and finally put it down on paper here.
Another huge influence on the 2 Position Scale System was actually Fourths Tuning (E, A, D, G, C, F). If you tune your guitar to fourths it becomes symmetrical, and you don't have that bump of a major third between the G and B strings that warps every scale pattern, or chord shape, or anything you do on guitar for that matter. I found that a lot of people who got into Fourths Tuning were sticking to the same method as standard tuning for learning scales, which seemed like a waste of time to me. In Fourths Tuning you only ever need learn two patterns for each scale as the tuning is completely symmetrical. Check out the tutorial and apply it to Fourths Tuning, and you'll see what I mean.
So ask yourself this: Does your method for learning scales match your playing goals or ideals? If you're stuck in a rut there's a good chance it doesn't. Turn the thing on its head and work back to the method from your goals.