Why do so many people refuse to read online? (See Details)

I recently made a post on a different site. To summarize, I was expressing disappointment and confusion over people’s unwillingness to read profile bios. On this site, I State my intentions in my bio. I’m only there for friends, nothing more. And yet, no one will read it any many message me seeking more than friendship. When i tell such people that i clearly state my intentions in my bio, they often say that they didn’t read it because they just didn’t want to or don’t care. So that was the basis of my post.
The comments, so far, are all complaining about how long my post is - that it’s too much to read and no one has the time for it (the length of the post was a little shorter the length of this post, as it is so far). Ultimately, they’ve proved my point - people are too lazy and full of themselves to take 30 seconds to read something someone has to say - or even skim it. However, it’s still incredibly annoying. I just don’t understand the mindset as-is, and they fact that people insist on being so unnecessarily rude in response is disheartening, to say in the least.