Hi Nick,
I flew weightshifts at Ince Blundell before moving over to do the full commercial licence here in the states. I can't answer your question as to why there is not much to do with microlights, but no doubt there will be a dedicated area in the future should the need arise.
I know that Ince Blundell has its own Yahoo chat room.
Here is the link for your enjoyment:
http://uk.groups.yahoo.com/group/Inc...ellFlyingClub/
Hope that helps
Andy