It's a trade-off. They're trying to avoid bad comments, spam, etc. It really doesn't take much to get to 50 points -- just a tiny bit of participation. But that

It's a trade-off. They're trying to avoid bad comments, spam, etc. It really doesn't take much to get to 50 points -- just a tiny bit of participation. But that requirement increases the likelihood that you're a real person, probably not some troll, and willing to participate in the community in reasonably sane manner. It reduces the amount of moderating that is needed, and makes the community better as a whole, I think. I think it's perfectly reasonable.