Maybe 5% of cruisers on DCL visit these boards, of them, this thread is active but has mixed views and other threads like happy with DCL Alcohol policy have been formed and some people are taking the sensible view to avoid the thread or lurk and not post. The Disboards doesn't have the power you infer, it can cause some poor DCL CMs at the call center, ( who didn't bring the policy in) a lot of grief and complaints making their day on the phones harder than normal.
I think the few think that ganging up to encourage letter writing, ( one thread) or calling in will not have any affect. Smoking policy was changed and stuck that actually had more reaction.
The smoking policy is not a fair comparison, especially when you look at the american side of the pond. Here it is just accepted here that smoking is being banned anywhere that is public, so this happening on the cruise ship mirrors what we see here.