I do not think anything much will change some people and putting un Draconian measures won' t help. We have over in the Yorks &Hunberside board persuaded a long term member who contributes but has not made a report, to make a report. Its a good one too and thankfully he will make more and help others to put reports in.
In life we have alsorts of people some like to get involved, some do not and we will just have to get used to it. We can only persuade nicely, being bombastic, sarcastic, sanctions, and horrible is not going to help .