Are you really 'not sure'?
It's because the OP didn't write 'do you think people ever select for gender doing IVF'. The answer is, yes, clearly people do. The OP said some people treat IVF like ordering a designer baby. She then described some extremely unlikely situations as if they were commonplace.
The reason people are 'giving her a hard time' is because this is goady shite. It feeds into the idea that IVF is fairly easy. I'm in the middle of doing IVF at the moment, and it is not easy. It's grim.
But you would be amazed how many people buy into that idea that it's easy. Men and women. The last cycle I did, I was working a physical job, and there was a point when I simply couldn't do it - the clinic told me not to lift anything heavy; you risk ovarian torsion, which is agonising and also potentially pretty awful for your fertility - and you would be amazed how many people expressed confusion. 'But how come it's not just like any other monthly cycle?' (Er, because I am doped up on a ton of hormones and my ovaries are the size of oranges, you idiot.)
People also think it must work pretty well. Because if you read nonsense like the OP's posts, wouldn't you assume it works most of the time? And that hides the reality that, most of the time, IVF doesn't work. Yes, it's a wonderful technology, but even for young, healthy women, it is often a failure, and a gruelling, expensive failure at that.
That's why the OP's post is making people cross.