Could someone please elaborate on this "lower boards" and "upper boards" concepts? I'm assuming the first term describes an active group of users from a part of the Bay 12 Games Forum which is not connected to DF?
The upper boards are boards about Dwarf Fortress. The lower boards are about... Sexuality apparently? It's pretty much just a mess of people talking and playing forum games and whatever with no real purpose. The name comes from their position on the board index.
Upper boarder here, gonna stick up for the sexual orientation & salary questions. These are common demographic survey questions, just phrased slightly differently from how they usually are.
Salary survey questions usually give salary ranges rather than asking you to specify your salary. I suspect if the question had included range options (with a "prefer not to answer" option) rather than asking you to specify, you wouldn't have blinked. The demographic information that salary information gives is a rough picture of the class distribution of the community in question.
Sexuality questions usually give options for hetero/homo/bi, and I suspect no one would have blinked if it had been phrased that way either. The Kinsey scale just gives slightly more nuanced answers, for people who are interested.
As for sexuality's relevance to Dwarf Fortress, I think it's relevant in more ways than we hetero folks tend to think. As an obvious example, I doubt that anyone not-heterosexual had a negative reaction to the sexual orientation Easter Egg in the latest release.
Yet you'll notice that other common demography questions, like those pertaining to race and ethnicity, are totally absent, even in the nuanceless version used by, for example, US federal government. To me, my family's history is a way bigger part of my identity than categorizing the portion of instances that I'm attracted to one gender over another.
And the sexuality thing isn't an easter egg but a full mechanic. More than a few people don't like, on mechanical grounds, the fact that animals can be and often are exclusively homosexual or asexual because it hinders breeding plans (and it's not really reflective of reality for the vast majority of animals) rather than because of some ideological grounds. Of course, this is for people that play Dwarf Fortress, I don't know the opinion of the lower boards.
While I don't know how common it is, I've seen some somewhat joking questions in actual large scale surveys as well. Usually in the middle of longer surveys, probably to keep people interested instead of getting halfway through and getting bored and deciding to stop taking it. Depending on what the question is it may actually lead to a result worth investigating further even if the joke question itself isn't useable. For example the toady one question may lead to a more serious question next time about the community's opinion of Toady One depending on how the answers lay out.
It might be interesting to as something like "do you respect Tarn Adams primarily as a person or as a creator of a game you enjoy?". That would get a feel for a "cult of personality" vibe compared to simply enjoying the game as a game with Toady's existence being a mere accessory to that – I feel that both positions exist in non-trivial number.
bay`12: the place where the simulated mass murder of children is acceptable and even encouraged, but a demographic survey is controversial.
The difference is that one of these things is related to a game made by Bay12Games (the subject of the forum) while the other isn't.
Some didn't like how it reduces your dwarves' fertility rate in the game. People made instructions on how to edit the raws to remove the feature and ensure breeding in your fort. I don't think anyone had any moral objections to it, however. (At least that weren't removed before I saw them.)
Toady doesn't normally remove opinions unless they cause a shitstorm (and even then, often only if it metastasizes) and when he does he says so in the thread.