This might change. Subscriptions are the new thing and customers expect more. Personally, I won't accept a gym membership anymore that I can't cancel in 3 months max.
To be clear, I'm not talking about a subscription where you're locked in for a minimum of 12 months or whatever. I could cancel any of the gym memberships I've ever had with only one month's notice. I just never did. (Because if it occurred to me to think about canceling, I'd say, "No, I really should start going. I'm going to start going. Yep, I definitely am." And then not go.)