With the new steam Mod Market, that has been implemented for Skyrim only, at the time of writing, BIS appear to be attracted to a more moneybased Modding community.
What's the Steam System like?
According to that System, Modders have the Option to charge money for each download of their content. The transaction is then split between Steam BIS and the modder, where the modder only gets a 25% cut, even though, he did ALL the work. This System is so flawed, that I don't even want to start spamming the problems in this ticket.
Here is a different Model I would suggest for Arma.
Whenever someone buys Arma 3, because he wants to play a specific Mod, then the modder should be rewarded for basically selling one more copy of Arma 3.
The new Player gets a function in the Main menu for up to 48 hours after the first start, where he can choose one or more optional Mods, that convinced him into buying Arma 3.
BIS is then collecting that information and splits 25% of the (currently) 44,99$ - 59,99$ price for Arma 3 between the mods, that were named by the new player.
Additionally give the player an option to send a message to the devteam of each Mod
This way the modder gets some financial and moral support for his work, BIS sells more games and the player feels like his money is being appreciated and handeled with care. Everyone wins and mods are still free.