It isn't inherently bad. The people who end up on charge of them almost always are. It's not something humans can have in a way that is beneficial to most (or all) of those affected by it.

That said, a single decision maker is also not good. Right now the US has (supposed to, anyway) three branches of power that are each intended to prevent the others from doing whatever the hell they want to do. This was seen as a good thing generally, and other governments have modeled theirs after the US's.