There are many users with the obsidian rank, but there are less plus users. At the moment, we have 12 moderators, so the amount of reports they receive is overseeable. If obsidian users would get access to the /report command as well, the moderators would have to handle more reports than they can. I think this feature should stay PLUS only. I've been thinking about another perk for obsidian users, though: Double votes! The vote of an obsidian user would count twice, and if they'd buy plus the vote would count thrice.