I would agree with that. Maybe there is a need for "Friends of Wikimedia UK" membership? In the same way that you are a "friend" of your favourite charity e.g. The British Museum.
There already is, that's what Gordon was talking about. You can be a "member", which just means you pay some money each year and just generally support the chapter, like a "friends of" thing, or you can be a "guarantor member" which involves paying slightly more each year and gets you a vote at the AGM and means you can stand as director. It also means you are liable for up to £1 of the company's debts if it gets wound up (goes bankrupt).