I respect everyone's life choices, but sometimes good points are made by the complex shitstorm people have made it all out to be. Masculinity is a fabricated concept, which is okay by choice of the person who follows such concept. Same with literally the rest of it. I don't see why this makes them so offended, they can live anyway they want, most the time over-sensitive hostility is just a front for someone who wants to be taken seriously at someone else's expense.
Sex, Sexuality and Gender are different concepts. Sex is what you biologically are. Gender is society's and one's personal perception of the sex. This is based on notions of masculinity (society's ideal of a man) and femininity (society's ideal of a woman). Sexuality is what you are attracted to. masculinity is related to concepts like strength and independence, while femininity tends to be connected to caring and fragility. But that raises questions: if you're a biological male, yet are caring and not muscular/strong, you don't fit society's ideal of a "man". This has often been seen as being "feminine", and in a sense more than two genders has been accepted by society for ages, just not the other gender concepts themselves. A male after all is not biologically female, yet is perceived as female in his behavior in this hypothetical case. But that means that there are more than two genders, since it's possible to be a sex and yet not fulfill the ideals of that sex. But wait, i barely started. Masculine and feminine are not interchangeable nor opposites. You can fulfill a man's ideals yet borrow from femininity, like being a strong tough guy that nevertheless deeply cares for family. Femininity and Masculinity combined do not cover all bases. But that means that there's not just a binary system of man and women, nor a discrete divide between them. You can fit certain ideals (e.g strong) yet not fit others (IE you can care). So the only logical deduction left is that gender is a spectrum, made up of numerous concepts. It also doesn't take much effort to deduce sexuality. After all, everyone probably has an ideal partner in mind that fits their sex's ideals, yet not every ideal has to be weighed equally. You could marry a muscular man that deeply cares or takes pride in their look. Such a person would have masculine (strong, muscular) properties but also feminine. But attraction to a person goes further than that, since you can like certain features or even simply taste in music etc. So sexuality itself is also a spectrum, depending on your level of attraction to these different concepts. You could ask yourself if sexuality ought to be purely defined by the biological aspect (because if a concept becomes to muddled, it has no purpose anymore in daily life). Of course that leaves us with the big question: if society decides the ideals upon which this is based, isn't it in a sense arbitrary? well, yes. People are people, and can come in many flavors, ideas and forms. The concept of gender is basically trying to fit people into a box because our primal instincts like to box things. You could seriously question whether the concept of gender itself isn't simply outdated, since even if they were built on reasonable ideas ages ago, modern technology has rendered many male-female differences null and void. I haven't even touched the sexes themselves, since by the logic of binary features (IE reproductive organs), you can easily conclude there ought to be four sexes (male / female/ male+female/ absent both features), if not even more if you count breasts as separate organs (since men are perfectly capable of having them, the machinery is there but it's not on). This complicates the gender ideas even further. The last question you may ask yourself may be "why this / why now", and the answer is simple: numbers. Statistically the distribution may be the same, but the absolute numbers of humanity have increased, a lot. While previously it was fairly easy to suppress any world-complicating view, the presence of the internet has made it easier for like-minded to come together and realize they're not so rare as they're made out to be. Greater absolute numbers also means greater visibility to the world. Not to mention that the church liked it's position as a thought police and branded any dissenting thought as heathen, because although they were all about abstinence and purity, they were nevertheless greatly concerned with how people were doing it.
To be fair, I believe in liberty of a gender spectrum. People can believe they're a gender defined in-between some standards of something. People can believe they are male yet just act feminine because "society has it wrong" and sewing and cooking are important ******* skills for independence, a la "made up constructs don't exist". People can also just do the male doing masculine things deal for themselves, as long as they don't look down on the skills other living human beings bring to the table just because they "act different". Then, even expanding past "gender", there's eating pork or not. Some people say not eating bacon is unAmerican. That's pretty divisive, why can't people have an opinion on food, for WHATEVER basis their reason falls on? Same bacon-loving SoBs, don't like brussel sprouts, but nobody belittles their lack of taste over the brussel sprout issue. One thing I can see as "silly", is people demanding respect for their spectrum-based gender, yet belittle constructs of religion or cis-genders. Both sides are acting "defensive", when they're really "preemptively offensive", and both sides need to cut that **** out.
In your opinion, in the sentence "gender pay gap" gender isn't properly used, isn't it? Well, this gender pseudoscience reminds me of middle ages theologists wondering if adam had belly button xD Of course, be however you wanna be and like whatever you... like? But please don't make a new science out of a retrograde view (men must like football and fart in public) of human behavior. This whole thing is just absurd. This is just rude to people who have lost organs due to cancer for example. Go to the next march against breast cancer and shout YOU ARE LESS WOMEN! Although maybe they deserve that as they have, at least in my country, stigmatized men with breast cancer.