To get you up to speed as to why this has been controversial, all the way back in 2015, Bethesda partnered with Valve to bring paid mods to Skyrim via Steam. However, this particular update has gone down rather badly with Skyrimmers, as it has reintroduced a paid mod platform into the game.
Sure the game is several years old now, but it is still very popular with players, so why not give the game a boost if it needs it. Bethesda has released a new and quite chunky update for Skyrim Special Edition, which in itself isn't all that remarkable.