My anecdata says the exact opposite. The HN crowd seems (to me) to be very, very against walled gardens.
It's bad for consumers to repeat corporate marketing jargon.
And those that just paid a thousand dollars have Post Purchase Rationalization.
Heck those that actually own heavily marketed Veblen goods (Tesla/Jeep/Apple) products typically do have this Bias.
It's people without skin in the game that can think the most clearly.
I think you are conflating two separate conversations with only a small overlap.
If they don't, then it's a bit deceptive. I'd fully expect to be able to buy OEM parts for any car I buy, and to have the car repaired at an independent shop. If you're defying the norm it's your responsibility to inform your customers.