(moving this to the Feature Request forum where the conversation is more appropriate)
I don’t mean this flippantly, but saying that other applications do something a certain way doesn’t make much difference to us. Our product is not the creation of copying features and behavior of other applications, but a unique product of our own creation and design. If a feature is compelling and necessary, that’s another thing altogether, but a feature’s inclusion in other software does not by definition make it compelling for ours. Perhaps the philosophical difference in moderator roles in this regard is due to a difference in what the ban feature does? In ExpressionEngine, banning gives you the option to ban the member, ban and delete all of their posts, and even ban the IP address.
As for trusting moderators, I agree you should be able to trust them, but that doesn’t mean that powers should be distributed equally. For instance, on our forums, our technical support staff have moderation abilities. But it would be inappropriate for them to make a decision about whether or not a user should banned, and which of the three options mentioned above should be used. I’m not diametrically opposed to adding this as an option for site creators to give as an allowed moderator action, but like all feature requests, I do so enjoy a good convincing. I mean, if you trust them so wholly, why not just make them Administrators?