It's based on biological fact. Gender from a biological stand point is male and female. Gender identity is purely psychological.
Just like how one should respect the beliefs of others (e.g religious), and respect how someone prefers to be addressed (e.g name, title), there should be recognition of those beliefs and preferences. But when there's an attempt to alter the biological science of what constitutes a gender, that's where it becomes illogical. That's where such images can be humourous. For me, I find it brilliant. Not because I am intolerant, but because it exposes the biological fact vs psychological preference.