That's only a pretext, Genn could have agreed to be accomodating while keeping some pride and having some relucdance into following Varian and Anduin's orders instead of having been turned into one of their fanboys.
And the writers did the same with Malfurion and Tyrande, turning them into incompetent and impatient leaders when they have shown their worth against the Burning Legion and the Highborne during the War of the Ancient and when Tyrande was willing to wait ten millenias before marrying Malfurion, yet in MOP she's depicted as unable to use the slightest amount of patience into taking a temple held by the Horde just to make Varian shine.