hopefully being in retail i can shed a little bit of light on this. I go through this all the time.
First no need to get mad at Cabelas persay. They most likely use a serperate financing companies as do 99 percent of all retail companies.
Second your lucky they are lowering your limit. as others have said most companies have intiated an inactive period. if your account is inactive for a said period of time is is automatically canceled. mainly to free up some money to give to new accounts.
third it is not always a good idea to cancel an account. sometimes it can have a negative impact on your credit. not on your score persay but on your actual credit. as you see different credit companies look at credit different ways. some dont even look at your credit score.