I joined in the 70's as a schoolkid to join an organisation that had led rides beyond my back door. Despite riding a bike that was no better than a BSO, with cut down jeans and a baggy wool jersey, they were some of the best and most exciting rides I had on a bike. Becasue i wasn't prepared, they were also some of the (to me then) longest, hardest and most bonked-out rides I've ever had, but I came back for more. I've been a member ever since except for most of the 80's when I needed a racing licence, so wasnt going to pay both them and BC. After my racing "career" rejoined CTC. I mainily join cos as a responsible road user I want 3rd party insurance and legal aid to help me should i need it, either arising out of accident or some unfair prosecution (due to riding non matching tyres). And they are the organisation that best support the urban cyclist. I'd quite hapily pay £10 less to forgo the mag tho.
The organisation these days is not what it was back then in terms of local activity. Back then we had Easy riders, which was basically teenagers taken out by an adult all day, social section which was adults, couples, tandems etc, at a social pace with a pub lunch, family section which was trailers, kiddy seats etc and hard riders which was a hard racing run on bikes with mudguards and each of these might have had 20-30 riders every week. Nowadays there is a midweek evening beginners ride with a couple of shandies thrown in, in summer, which i go on for social reasons - all types of bike, both sexes, all ages and I do one or two sunday rides if its one billed as hard and all day long. There is only one sunday ride and that is usually an easy one catering for relative beginners, so my activity is limited.