You've pretty much gone over one of my main reasons for deciding that if I ever make a mod, it won't require permissions. Putting it in a modpack just saves the user time. Seriously, why should I care whether someone is giving his friends a copy of my mod so they can play it together? As long as modpacks give credit, I'm not losing anything. I'm sure modders have their reasons, but as far as I'm concerned, permissions are just a huge pain in the ass for both modders and mod users. I wouldn't want to waste so much time and effort on something which benefits nobody, least of all my users.