I'll do my best to answer you. And of course, I too am not trying to be contentious, just offer my opinion as best as I can articulate it.
I wasn't arguing that because something has always been then it must necessarily be so now, I was pointing out that redefining gender to be a choice one makes based on how they feel is a new phenomenon. Of course this stuff has been around for longer than 5 years, but it wasn't mainstream before then.
I do agree with you that the reason this has all come to a head is because of the internet, though I suspect we disagree on what's propelling the change.
Of course people are attempting to redefine the concepts of gender and sex. It's been happening for years. Gender, for instance has always, until recently meant something much like this dictionary definition: "the state of being male or female (typically used with reference to social and cultural differences rather than biological ones)". Now many are saying it means pretty much whatever you personally feel like it is. And there's the problem, if there are more than two genders, then there are necessarily potentially over 7 billion genders. The only limit is how many people are alive. At the moment we're up to what, 70? 300? Believe me, it will only go up. At what point will you begin to agree with me? 1000? 10,000? At that point, the word and the concept itself would have become completely meaningless.
I personally don't see why people who don't adhere to traditional expressions of gender can't just leave it at that. I'd argue that no one adheres to all traits which are traditionally attributed to their gender. But that doesn't mean that their gender is no longer linked to their sex, it just means that they're an individual, as we all are.
Lastly, a person's name is not a gender. As neither is their job, or where they live, etc. Some traits are intrinsic, some are not, it really is as simple as that. If William wants to be called Stuart, of course I'd have no problem. I have no problem calling them Jenny either if that's what they want, just in case you were wondering.
Oh and no, my standpoint doesn't affect my day to day interactions with anyone, and I don't see how it possibly ever could. If someone says to me that they're neither a man or a woman, but rather genderqueer, it has the same affect on me as someone telling me Star Trek is superior to Star Wars, as in, I'd just think, okay that's your opinion, I don't agree with it, but you have a right to your own opinions.