Agreed, making the forum 'Members Only' would be a real shame, although there should be (and is, of course!) a members only area, where more select information, club member discounts & benefits are accessed.
There are A LOT of AC enthusiasts who access the forum, with valuable contributions, valid queries, and who might otherwise struggle to make contact with AC owners, for whom membership would not be a reasonable expense or of sufficient benefit, but as a flip-side to that coin, I believe there are many, many members who 'don`t do computers' or access the forum, which is a pity.
PLEASE consider the open forum as a valuable tool which has probably attracted additional members to the ACOC, promotes The Club in a positive way and is an asset to the Club, it`s members and enthusiast non-members alike.