Not much I can add to what's being said, but as someone who published a game that's been at least slightly modded in the past, I thought I would pop in and confirm the dicey nature of these sorts of things. Personally I love how companies like iD Software, Valve, and Bungie embrace modding communities, but it should be noted that they put in preparations for mods from the get-go. (For example, Classic Doom's framework was specifically built to be more accommodating for mods, whereas Wolfenstein 3D - iD's previous project - was not.) However, it's a risk/reward sort of thing that not every business may want to undertake. A company may rightfully decide that they don't want to invest in additional time/resources for the mere potential that interesting mods will crop up. Or, they may simply want to focus all of their attention on new projects. So while it's always cool when heavy modding is possible, it's not necessarily something that they owe us. It should always be a choice.