I see your point, and maybe "the younger son's 'humility' is false humility" is true. I'm assuming it isn't true, not based on the verses of the parable itself, but on Jesus's lead-in about repentence.
If we assume the younger brother truly repented then that affects the calculation.
Also as far as the "conditioning" to bad behaviour, another consideration: the younger son's experience PRIOR to coming home was not one of positive conditioning. We know that sin is also its own punishment. Sinning boldly results in bold suffering.
I agree, but the way the parable is worded, it looks like he was on his last straw, so to say, before 'repenting.'
We know that sin is also its own punishment.
In the long run, yes, but we are drawn to it because it "feels good and is comfy." It's something we do 'naturally.'
Sinning boldly results in bold suffering
Touché. :)