I think you misunderstand what I am saying. If you watch the first pitch Bustos hit in the above YouTube clip, it is way off the outside edge and way low. Bustos was still able to get the barrel of the bat on that pitch even though it was thrown in a great location. It was a great pitch about 7 inches off the plate and about 8 inches off the ground. Now, take a pitch shoulder high about 8 inches off the inside edge of the plate. It is much harder to hit that pitch with the barrel of the bat. I'm not saying it can't be done, I'm just saying it's a tougher pitch to hit, and that type of high and inside pitch is a great pitch to throw when ahead in the count.
A pitch on the edges of the plate are good pitches, not great pitches. Pitches down the middle of the plate are bad pitches. Great pitches are the pitches off the plate the batters are forced to swing at, and in my opinion this type of pitch is tougher to hit if it is inside rather than outside.
Most pitchers and coaches in every level of fastpitch are just too afraid to throw inside because of the small margin for error, not because it is a less effective pitch. Also, throwing high and in helps set up the low and out pitch.
Len