Are you perhaps more concerned about software that keeps nagging you about the same thing over and over again than about the wording in particular? Because badly designed software will do that whether you told it "not yet" or "no".
While I can see the frustration by repeatedly using such software, it seems fair that a well-intentioned UX designer would use "not yet" if they found it works better for a majority of people. What then matters is that they respect the intent of everyone by not bringing the choice up again.
I think 'well intentioned UX designers' who do this are in the minority, honestly. Or naïve. Per derefr and latexr's comments, it's a dark pattern with an ulterior motive.
To your question, I'd say it's a false dichotomy.
The repeating behaviour and the 'not now' are two sides of the same coin. Per the original post, and my experience, those 'not now' buttons keep coming back.
And, for the sake of argument, how should respectful software behave? If I clicked 'not now', are you _ever_ going to ask me again? If so, how do you decide on the time-period? If not, why make 'no' more complicated than 'yes'?
> The repeating behaviour and the 'not now' are two sides of the same coin. Per the original post, and my experience, those 'not now' buttons keep coming back.
So you're using "not now" as a shortcut to identify malicious design. That's fine but personally I'm not. I would go as far as claiming as most people don't feel this way about such a tiny wording detail, but I obviously haven't ran any A/B testing to confirm either interpretation.
> And, for the sake of argument, how should respectful software behave? If I clicked 'not now', are you _ever_ going to ask me again? If so, how do you decide on the time-period?
Honestly this question seems bizarrely focused on making the software give you a definite promise on what it will or will not do. It's a valid design question how to respectfully prompt the user for choices, but if that's your concern then this specific wording choice is an unimportant detail to get stuck on.
> If not, why make 'no' more complicated than 'yes'?
The reason was given my my opening argument: "no/yes" demands a conscious choice whereas "not now" doesn't. "not now" is plausibly less complicated than "yes" for a majority of users, and cognitive overhead generally matters more to people than imaginary contracts about future choice prompts.
> this question seems bizarrely focused
You did say "playing devil's advocate", and you asked which of the two I was more concerned about. So I think it's OK to explore the arguments either way!
I'm going by gut feeling here, so I'm not pretending to bring any data to the discussion. My original post was "commonplace UX pattern A gives me this feeling B".
Modern UI trends which seem to prioritise the wishes of the product designer over good UX. And I feel that _that_ is driven by metrics that don't have my best interests at heart.
> "no/yes" demands a conscious choice whereas "not now" doesn't
These messages are often displayed in modal popups (e.g. the original post), or otherwise intrusive fashion (e.g. sign into BBC News website). So if you're asking this question you're _already_ forcing the user to read a message and make a choice. If the user isn't ready for a conscious choice, maybe you shouldn't be asking them to make any choice.
Going back a few years, a piece of software with options would put them in a preference panel. If the user wanted these features, they would intentionally seek out how to set them. They would be in control. And they would be both sufficiently contextualised and intent-driven to make that yes/no choice.
Maybe these days with rolling or frequent deployments it's a challenge to communicate new options. But I don't think that applies in many of the manifestations of 'not yet'.