When I criticize, I'm a genius. I can go through a book of highly-referenced scientific articles and find errors in each of them. Boy, I feel smart. How are these famous people so dumb?
But when I write, I suddenly become stupid. I sometimes spend half a day writing something and then realize at the end, or worse, after posting, that what it says simplifies to something trivial, or that I've made several unsupported assumptions, or claimed things I didn't really know were true. Or I post something, then have to go back every ten minutes to fix some point that I realize is not quite right, sometimes to the point where the whole thing falls apart.
If someone writes an article or expresses an idea that you find mistakes in, that doesn't make you smarter than that person. If you create an equally-ambitious article or idea that no one else finds mistakes in, then you can start congratulating yourself.