My partner of the last six years is trans. Your post doesn't strike me as hate speech, but what Hacker News commenters seem not to understand is that making overly general statements about entire groups of people can often lead to an oversimplified view of the situation (see what I did there).
Let's start with the assumption that people can and do learn to "want" to be a particular gender. I am not an anthropologist, but I feel like this is a pretty uncontroversial take, and is the mechanism for how cis-gendered people learn to follow the gender norms of the culture they find themselves in. This is the key difference between gender and sex. Gender norms seem to be a cultural universal, but the form those norms take is dependent on time and place.
What this means is that in any society there are two sets of behavioral norms, one for perceived men, and one for perceived women. If a person in this society has a strong preference about which set of norms they prefer, and if the set of norms they prefer doesn't line up with their sex, you have the potential for that person to identify with the other gender. The term "transgender" is new, but behaviors associated with the term go back as far as you care to look.
So you have this potential tension where a person might prefer the gender norms of the other sex, but you also have the fact that questioning norms of any kind in a society is always somewhat taboo. A few very dedicated people would live their lives as the other gender. Many more probably would have liked to if they were aware that it was an option, but were not (in other words, even questioning a social norm can be difficult if there isn't already public discussion about it).
So if the sudden perceived increase in trans people seems like a sociogenic disease to you, I can see how you might think that. I can also see how hurtful it is to many people to frame it in those terms. If we take a closer look at the linked paper, they hypothesize that one of the drivers of the tourettes-like disease is attention seeking behavior. Are there people who decide to transition ultimately because they believe they will get more attention? I'm sure some do. But thinking that is the motivation for most trans people is a very hurtful overgeneralization and is unhelpful because it is just wrong. The trans people that I am personally acquainted with don't want more attention. They want less of it. If you even glance at common discussion topics in trans discussion forums, you will see that there is a lot of discussion about "passing". Passing doesn't seem like attention-seeking behavior to me, it seems like the exact opposite.
Does social media have no role to play in explaining the increase in people who identify as trans? It probably does have some role there. But its only accelerating and amplifying trends that already existed. LGBT+ issues in general have been getting less and less taboo to talk about for the last several decades. The internet and communications technology more generally is exposing people to more cultures and norms. My hypothesis is that there were many preexisting people who were unsatisfied with the gender roles that they were expected to fulfill, and that growing acceptance and discussion of LGBT+ issues made them realize that there was no reason to keep putting up with them anymore.