Similar to this, but I'm interested in why.
Why am I limited to identifying 40 useful questions and answers per day? It seems strange that a website dedicated to community editing would limit that to a hard count/day. I'm guessing the concern is indiscriminate upvoting. But you have to make a determination like the US legal system does. A guiding principle is that we'd prefer to allow 1000 guilty men go free rather than convict a single innocent person.
By limiting me to 40, you're preventing questions or answers that deserve getting upvoted. That's the wrong compromise.