That is a valid point, but one can also point to the fact that from the day DD took over, until the Bello call-up, the only real impactful pitcher to come up from the farm was Houck.
The lasting effect of such a long drought is significant.
In DD's defense, he did not trade away Houck, Bello, Crawford, Mata, Walter, Wikelman, Murphy and Perales.
The vast majority of our best young pitchers are products of DD. Only Whitlock, Wink and some far-away prospects are on Bloom.
He deserves much criticism for this.