I recently joined the CTC, mainly to get the insurance and the magazine is sometimes good.
I had no other expectation from them. I sometimes see CTC members at a local cafe while I am cycling on my own. They make it very clear that I am not one of them.
I once telephoned them regarding their holidays after they failed to respond to my E mails. They were very clear that I am not welcome.
They are essentially a club. Like any club it serves its members. But when I joined, I knew that I am not joining the club but was happy to take the insurance.
How did you know he/she was a CTC member? You mean you know them to speak to, but they don't want you to ride with them? Rude, then, not CTC rude, just plain rude.
Here the CTC are welcoming, they have a Meetup page with their rides, I don't even think you have to be a member to come along.
Most experienced riding folks I know, or folks that have a job in cycling, are CTC members but belong to other organizations too, like GoBike, Spokes, or indeed the Belles on Bikes. They may also belong to racing groups.
I don't see how a CTC member could say "I'm not riding with you because my membership is higher than yours".