@curmudgeonly007 I can see why this would make you feel uncomfortable.
My interpretation of this rule is that it is in the context of patriarchy.
First, we are all in this system where men have been expected to 'court' women to a certain extent, and the idea is that if they don't do that, they don't value you. Because we can't escape the toxic views about gender roles that all people secretly hold.
Second, women actually are in a worse position in society, so men should step up and pay for dates. (By way of example, my disgusting ex has dumped all childcare on me so that he can excel in his high powered job, and I literally can't get a similar kind of job without harming my daughter. Obviously he feels aggrieved at paying the bare minimum in maintenance, which is a sadly typical attitude). The idea is that if they aren't willing to do that, fuck'em.
Third, many men aren't generous and this comes out later in the relationship (again, my ex is a great example of this - he's basically rich but resented ever spending money to make me happy). The idea is to screen out men who are selfish like that.
Fourth (and this is partly my own personal philosophy), people don't value things that come easily. Being an easy, 'cool' girl from the start encourages men to devalue you and take you for granted
I'm not saying I fully support these rules in all ways, but maybe this helps to explain.