Imagine, if you will, standing on a stage. I know many of you have had limited experience with that, and that what experience you've had involved being pushed there by school events ... but imagine it nonetheless. Imagine a much bigger auditorium that the one in your school, more like the sort you would encounter if it were your job to speak to people. It's a fairly intimate setting; the audience can see you very well. Because of the lights, however, you cannot see the audience.
Now imagine that your reason for being there has nothing to do with your job. You haven't been asked as an expert in your field, you're not there to give a seminar to people in the industry, you don't represent a company, an organization or a cause. No one in the audience has come because they believe what you believe, or even with the expectation that you're going to say something worth hearing. They are just there. You have no friends in the audience, no family, no acquaintances from your various activities. These are all total strangers. Nevertheless, they are here to judge you.
You might be getting some money for this. It might be enough to buy a week's groceries.
On the podium is an rendition of your speech. You've worked on it to make it as good as you can. Now you are going to read it. Only ... part of the condition of your being on the stage is that you are not now allowed to improvise. You knew it would be so going in. Because of the conditions, you're going to have to read your speech exactly as written. If there's a misplaced word, a sentence that doesn't really make sense, a concept that isn't entirely clear, tough. You're stuck with the speech you have before you. Now get reading.
Most people would work really, really hard on that speech to make sure there are no errors. They would go over it repeatedly, a hundred times if necessary, changing, fixing, adapting ... but in this case, this speech will take you 13 hours to read. It is written on 400 pages.
You should know that the whole time you're reading it, the audience will be free to shout at you, criticize you, leave, insist that you stop talking long enough for them to leave and then come back again, and so on. And when you're done, that same audience will feel free to abuse or praise you wherever they please, including in places where thousands more people - who have never heard of you or heard your speech - will freely have strong opinions about what sort of person you are, what you're like, how boring you are and so on. Many of these opinions will arise from people who rose in the first five minutes of your speech, shouting that it's boring as hell, and rushing out to tell others it's boring as hell.
All of this will be firmly in your mind while you're methodically going over your speech to make it perfect.
I'd be willing to bet, given those circumstances, most of the readers here would never finish that speech. They wouldn't willingly stand up and give it. Who needs that kind of stress? Who needs that kind of abuse? No one. Better to keep one's thoughts to one's self, where they aren't judged, where the merit one has is assumed, rather than challenged. Where one's opinion, lightly or markedly given, yet possesses an inviolability - or rather, the pure righteousness of one who doesn't have to prove anything.
Better that, then putting one's head in the guillotine.