It's a different case. They wanted to just grab the audio files from Fallout 3 and pack them with their mod. Bethesda said they can't allow that because the audio files are under different legal mumbo-jumbo and the actors association (or whatever it's called) would be able to sue Bethesda for allowing the redistribution of files that Bethesda owned the copyright for just Fallout 3 and no other game.
Our TTW installer does extract the FO3 files (from a legal English installation) into new temporary files, patches them, encodes them for the correct format (if they are audio files), repacks these new files, copies them into the TTW install directory and then deletes the temporary files (it does other stuff too like adding TTW files that don't exist in FO3 or FNV, or extracting and patching some FNV files too, etc.).
People suggested to the FO4 Capital Wasteland team that they should make an installer like TTW does, but they didn't like that idea for whatever reasons they had.
Interesting! I suspected it was the usual actors union bullshit at fault, but could you explain some more about the legal differences between the two approaches? So Bethesda has to shut down a mod that directly distributes copyrighted VO assets, but they're not obligated to interfere with the distribution of a tool that facilitates the same result on the user's end, is that it? Or is one simply easier to turn a blind eye to than the other?
And can you speculate on why TCW might not have wanted to do what TTW does? I know the project nearly shut down when they were told they couldn't reuse FO3's VO, before they decided to bite the bullet and record everything again, and then F4NV adopted the same approach.
Rusty is right in the above post. We can do whatever we want with the game files privately, as long as we don't distribute them, Bethesda is pretty chill about it because there's no law that prevents the user from grabbing assets from games they legally own and using them in different games as long as the user has the know-how to do so.
But as soon as someone starts distributing those assets without permission, then it becomes a copyright infringement, for the company that owns those files. Voice and music files are used by gaming companies under licenses (unless they are royalty free), so if Bethesda (in this case) goes ahead and gives permission for modders to use these files, then they themselves are breaking the legally bound license, which means they will get into legal trouble and can be put into court or have to pay a hefty amount out of court and then forced to revoke the permission they gave.
Fun fact, Bethesda asked the Nexus not to host TTW when TTW was first born, because Bethesda was worried we would distribute assets from the games. This was one of the reasons why we made our installer the way it is, it is also the reason why TTW is not on the Nexus to this day.
About FO4 CW team and their decision to not have an installer like TTW... I can only speculate, but I can come up with a few reasons why that might be:
First, getting someone that knows how to create and maintain the installer is a pain. TTW has had some versions delayed in the past because of this same reason.
Second, if the mod requires an installer then it can't be automatically installed by mod managers. So no one-click download and install, no including it in Nexus collections, users that are too used to this easy stuff will get problems installing it, it increases the customer support that a team needs to offer to users.
Third, maybe Bethesda telling them that they couldn't legally allow it scared the team and they decided to not bother with an installer, because what if Bethesda shuts them down later for other reasons and all of that?