If I remember right you could shackles a gold to demote it to a silver and damage it that way. Golds just don't feel the same since the change. A bronze is almost always better than most gold now
You could but Shackles was a sub-par card in general because it had no point value associated with it (positive or negative). Nobody wanted to run Shackles. In the cases where Shackles saw usage it was because certain gold card abilities were highly oppressive. If you didn't stop those gold cards by demoting and killing them you could lose the game. Barring that, you had to force them to be played outside of where the deck carrying them wanted to use them. Shackles in almost all of these cases was designed to give a backup plan, where if you failed to do this you still had a way to stop the gold. Even there it was reliant on drawing it.
It was the same situation created by the weather change when it first went live. Weather provided a point change but CS did not. This wasn't huge if weather was placed on the board off a weather card. It was a serious problem when weather was pulled from a unit, however. There you had the positive points from the unit and the damage tick off the weather. Clearing it with a CS meant playing 0 points in response to positive points + damage. This is why nobody used CS off a first light to clear weather unless it was a case where several weathers were on the board. Instead, everyone used mages and CS units. CS stopped being a weather counter.
One note on weather... It probably would have worked better if they kept weather as a temporary point reduction but instead of dropping units to 1 make it a flat point reduction. For instance, frost could apply a temporary -2 or -3 points to anything played on the row. In a nutshell, a temporary weaken effect.
Going back to gold immunity, the problem here was never gold immunity. It was oppressive gold cards. Taking out gold immunity to solve this problem didn't directly correct it. It removed part of the game to treat the symptom of the problem. The correct approach was to stop designing oppressive gold cards and change the ones already in the game. Attaching points to Shackles was another obvious solution.
Sure, you can say taking out gold immunity opened up card design. The irony is poorly designed gold cards is what was creating the issue to begin with. Opening up card design is not necessarily an improvement if it there is a history of oppressive gold cards finding their way into the mix and questionable card design in general. This pushes the game more toward removals as well, as oppressive cards are usually oppressive because you
have to kill them.