The theory is that the practices weren't physical/practical enough that Sark could see that he had shit for an OLine, probable shit for a QB, and likely shit for skill players outside Wisner and Baxter.
There is, for some reason, a disconnect between what Sark thinks his offensive players can execute and what they really can execute. It has been apparent for several years, although to lesser degrees. Exacerbated this year by the heavy turnover on O. There are a variety of possible reasons for that disconnect, but we have no real idea which one it is or if it is a combination of things. Possibilities include:
Light, NFL practices in off-season
Off-field issues, ranging from the known divorce and reconciliation, complete with child, to cuckolding and/or benders/relapse
Yes man assistants
Incompetent assistants that hide their incompetence (functionally equivalent to yes-men)
Pure stupidity and obstinance from Sark