If David Njoku's Cleveland Browns career is being brought to a premature close, the reason likely has more to do with former head coach Freddie Kitchens instead of his new agent new Drew Rosenhaus. Rosenhaus is simply representing the financial interests of his client and has no power to force a deal, although logically if a deal can be reached that benefits both parties, it will happen. The same situation happened last year with Duke Johnson, and the Browns were able to work out a fair deal with the Houston Texans.
Fans typically do not like sports agents because they are afraid they might spirit away their favorite players.