Before I say anything I would like to say that some of the things Pat does with his horses are amazing. Not to say that others don't do the same things, but videos of Pat riding bareback and halterless are much more available and accessible for the general public, therefore he receives more credit for doing it. I enjoy watching them. I don't use his methods.
Here is the thing with the Parelli program for me - it is marketed to predominantly beginners, the inexperienced or first time horse 'trainers'. Well of course it is, those with experience have their own tried and tested methods. While some people choose to incorporate some Parelli methods with other methods, they are not the 'norm'. The 'norm' is to progress through the levels with the exclusion of outside opinion or input.
The problem with the way the Parelli marketing is delivered, given it is sold as a program for 'anyone', is that in many ways, other training methods are strongly discouraged. This leads to a tunnel vision approach to training and is not the way to learn in any facet of life.
So, I can see that Pat himself is a good horseman (although it is unlikely he would be competitive in any dicipline by National standards) the way his training program has evolved is what attracts the criticism.
I have always said that if I thought a Parelli method would work better for me in a given circumstance, I would be open to trying it. I just haven't been in a circumstance yet where my own training methods (learned from many different horse people) haven't sufficed.
All horses deserve, at least once in their lives, to be loved by a little girl.