The solution I have heard before that I thought was the most interesting would add another arrow to the "Then why didn't he?" box at the bottom:
Because he wants his creation to be more like him.
He's just a lonely guy. He made the angels but they're so boring and predictable. They all kowtow to him and have no capacity for evil (except for that one time). Humans have the capacity for both good and evil, they don't constantly feel his presence, and they're so much more interesting! They make choices that are neither directly in support of or opposition to himself. Most of the time, their decisions have nothing to do with him at all!
Humans have the capacity to be more like God than any of his other creations.
That would fall under the "then God is not good/not all loving". You described it as if it were a privilege, but the capacity of evil causes indescribable suffering to us and to innocent beings such as small children and animals. If God lets all of this happen just because he wants some replicas of himself or because he thinks it is such a gift to be like him despite it, he's an egotistical god.
Also, if he gets bored of pure goodness, blissfulness, and perfection, then it was never pure goodness, blissfulness, and perfection for him. Those things, by definition, provide eternal satisfaction. So he either never created that (evil branch again) or he cannot achieve those states even if we wanted to. If he cannot achieve those states even if he wanted to, if he lacks enjoyment and entertainment and has to spice his creation from time to time, then he's not all powerful.
Also, many people argue the necessity of evil as a requisite for freedom. If God needs to allow evil so we can be free, then he's bound to that rule (and/or others): not all powerful.
Would they have been predictable had they never been created? Is conceptualizing an entire universe the same as actually creating the entire universe so it can play out?