I only recently became exposed to the phrase "if he wanted to, he would," {1} which is still going quite strong over on the clocksite. And like all dating and relationship advice, it can be helpful… but it can also create problems where there are none, particularly for neurodiverse folx.
The original intent of the phrase was to weed out those who simply weren’t putting forth any effort, or those who are "breadcrumbing" prior to or at the very start of a formal relationship. In both those cases, the phrase can be useful, although both Glamour and Mashable have pointed out there’s plenty of cases — such as anxiety — where someone could be interested but be unable to exhibit that interest.
Currently, the phrase is not just applied to before the relationship, but to the level of attention and affection paid to one’s partner(s) throughout the relationship. Again, this can be very useful; if your partner routinely neglects your needs and wants, that’s a problem.
But it isn’t that simple.
In relationships in general there is a cooling off of the big romantic gestures over time. (I’m talking about the big romantic gestures here like the "five year fizzle," not relationship "bids"). Should there be? Probably not; Gomez and Morticia Addams are wonderful role models here. But we have to recognize that is effort, and that life is chaotic and stressful. We have to remember that our partners are human and buffeted by the same exhausting BS. You have not always been the absolute example of a "perfect" partner, for absolutely understandable reasons. The same grace must be extended to your partner.
This advice of "if he wanted to, he would" is particularly discriminatory against the neurodiverse. On the autism side, we’re running all those social expectations on manual, so if they’re not spelled out in detail — and reflected back for understanding — then the odds that we’re going to get something wrong are MUCH higher. You may have to tell an autistic person that you do (or don’t) want a good morning text, or that you like hearing about their day, or other things that might seem "natural" or "normal" to you. {2} The ADHD folx have an obvious set of disadvantages, including executive dysfunction, rejection sensitivity, and simply forgetting (which is not just a matter of "try harder").
None of these issues give one a "pass" on meeting their partner’s needs and desires. If someone cannot meet your needs — for whatever reason — then that is when you have to decide if that price of admission is worth it.
But you can’t do that if you have misjudged their ability and willingness to meet your needs. Their past trauma (or yours), neurodivergence, anxiety, stress, or something as simple as a misunderstanding can drastically limit their ability, willingness, or understanding of your needs.
That means that you have to be careful on how you apply that phrase.
I recommend error checking: Ensure that the standard — your needs and what those needs being met actually looks like — is clearly stated and that your partner communicates back to you what the expectations are. {3}
That way you can be sure that you and your partner(s) are working together to make your relationship the best it can be.
After all, if you wanted to, you would.
{1} Side note: The gendered nature of the phrase is awful. If this is a standard, it should be applied bidirectionally and equally about the needs and wants of one’s partner(s), regardless of their gender. For example, this study looking at the sexual needs of the partners of men who are dealing with prostate cancer.
{2} This also applies to neurotypicals, although less so. One’s ideas about what an appropriate "romantic gesture" are — including whether or not, say, calendar reminders invalidate it — "common sense", which is not common, but instead a highly specific learned set of social norms.
{3} This actually helps if the other person is a bad actor as well; if expectations are unambiguously set, then it reduces the relationship version of weaponized incompetence.