I think the stereotypes for choosing a (heterosexual) partner are the following:
The ideal man is strong, street-smart, agenty, high-status, rich.
The ideal woman is pretty, emotionally sensitive, sexually inexperienced.
How this relates to supporting each other?
The attributes of the ideal woman are unrelated to needing support. Actually, when a woman needs support, that is a perfect opportunity for a man to demonstrate his strength and resources; this is what the “damsel in distress” trope is about.
But when a man needs support… well, apparently he is not strong/smart/agenty enough to help himself, so it kinda ruins his value on the dating market.
So the situation is not symmetrical. Loyal partners will support each other, but for the man, it has a flavor of “by supporting you, I demonstrate my value, which makes our relationship stronger”, while for the woman it has a flavor of “you lost some of your value, but I will support you loyally anyway”. (That is the “she’s not very happy about it” part. She now has to work harder than before, to get less of what she wanted.)
I think the stereotypes for choosing a (heterosexual) partner are the following:
The ideal man is strong, street-smart, agenty, high-status, rich.
The ideal woman is pretty, emotionally sensitive, sexually inexperienced.
How this relates to supporting each other?
The attributes of the ideal woman are unrelated to needing support. Actually, when a woman needs support, that is a perfect opportunity for a man to demonstrate his strength and resources; this is what the “damsel in distress” trope is about.
But when a man needs support… well, apparently he is not strong/smart/agenty enough to help himself, so it kinda ruins his value on the dating market.
So the situation is not symmetrical. Loyal partners will support each other, but for the man, it has a flavor of “by supporting you, I demonstrate my value, which makes our relationship stronger”, while for the woman it has a flavor of “you lost some of your value, but I will support you loyally anyway”. (That is the “she’s not very happy about it” part. She now has to work harder than before, to get less of what she wanted.)