A bit further down the page, he says “My concept of supposed distancing explains politeness as a result. If the speaker does not or cannot take hearer’s immediate involvement for granted, some distancing is unavoidable. . . . The pragmatic choice between aorist and imperfective imperative as distancing versus involving is also present in situations where the speaker hesitates as to whether his orders will be executed or not. A very clear example, and a comic reversal of hierarchical positions, is the discussion between Strepsiades and his son in Aristophanes’ Clouds 81–112. In an attempt to make his son take lessons with Socrates, Strepsiades gives him various commands (κύσον με, δός, εἰπε, πιθοῦ, ἔκτρεψον) that do not rouse his son’s suspicion. Only after an imperfective imperative (μάνθανε) does the son react: “What exactly do you want from me?” The son’s assertion that he will do as his father tells him (πείσομαι) makes the father continue in imperfective aspect (ἀπόβλεπε, σιώπα). Hesitation on the part of the son (“But these philosophers are madmen!”) leads to another aorist imperative (γενοῦ), only to be followed by an imperfective imperative (διδάσκου). The son’s surrender-like reaction (“What am I to learn then that may benefit you?”) shows that the father was right in his approach.” (39–40, emphasis original)
He also says that prayers tend to be in the aorist. I found that to be true. For example, the Lord's Prayer (Matt 6) is all aorists, as is Jesus prayer in John 17. Even in places where the imperfective aspect seems more appropriate, it is aorist.