Infeility is a common feature of seoli cell only syndrome because:

SCOS ( Seoli cell only syndrome ) aka Germ cell aplasia in which the seminiferous tubules are populated by only Seoli cells may show some thickening of the tubular basement membrane; germ cells are completely absent. Leydig cells are usually normal but on occasion are found to be reduced in size and number. Biopsy specimens from infeile men with total lack of spermatozoa (azoospermia) usually show one of the following conditions: Germ cell aplasia (Seoli cell-only syndrome) (29%) Spermatocytic arrest (26%) Generalized fibrosis (18%) Normal spermatogenesis (27%)