Frankly, I wouldn't describe your side of the conversation as "logical." I would describe your side of the conversation as containing a lot of case building statements, red-herrings, and blame/punishing statements all consciously or otherwise thrown at H to make him a living dart board. Yep, that's how it seems to me. This is the second conversation you've described in which you seem to me to mask cruelty and coldness with purported superior rationality and keen argumentative skills. However, your success in shutting down H comes from your rhetorical, rather than logical strengths. The two are distinct. Rush Limbaugh parades around as if he is a master of rationality and is quite persuasive in his efforts. But his spew, though effective, merely has the power of rhetoric, rather than logic or rationality, behind it.
On the other hand, I really liked your H's remark: "In the real world, people forgive each other over and over and still manage to have a loving R." He is quite right. In the real world, successful, healthy relationships depend on repeated forgiveness and allowing people space to grow.
I couldn't post to you for several days because (1) I was really, really sad to see you back to this sort of unhelpful posturing, and (2) I was at a loss as to what to say. Please take my remarks as criticism without judgment.
H: .... and you won't let me garden with you. Alternative response: There are a lot of reasons, my feelings are all tangled about it. When you rejected my invitations to garden, I felt unloved and abandoned. I still feel that pain, but it comes out as spite and anger now. When we garden together now, I feel a ton of resentment. I feel used and manipulated when you garden with me and then want me to do something with what you. I want a partner genuinely engaged in gardening. When we garden together now, I feel controlled when you criticize how I do things. When you make suggestions, I hear them as criticisms. When I sense impatience from you, I feel anger and resentment. And, to be totally honest, I get an unhealthy feeling of pleasure and distorted satisfaction about turning you down. But, I feel bad about myself when I experience that too. So, whenever the whole gardening thing comes up, my overactive defense mechanisms go on autopilot and I shut down the conversation in a way that lets me feel superior and sends a few darts your way. It is effective for sure. But, it is not really healthy either. I feel bad and lost when that happens. So I scale up my superiority and shut things down faster. Thing is, it is really hard to stop this cycle. And, I'm spiraling backwards. Help, I love you, I hurt so much.