The reason why we don't have monthly PvE events Is because of content... A monthly PvE event would require new content to be created, tested, and spawned in a month. Do you know how much manpower, money, and coding that would take? Now don't say that you would be fine with just different bounties and different colored ships and gear for rewards. I'm sure you would want each month to be drastically different from the other so that you don't feel like you're playing the same thing over and over. Pvp events are easy to make as all they have to do is just set some rules or add a mode for it. Nothing really new, nothing really the same.