Actually I found this which is somewhat close to your theory. This poster basically realized that conditioner-washing was softening the roots too much, thus leading to excessive shedding during the cleansing and detangling process.
This might sound like me. The roots of my hair were particularly soft and smooth (which I liked at the time).
As long as it grows back, that's all I care about now!
Excessive Shedding: Could Co-Washing Be the Culprit? | hairscapades