I liked the Rifleman because of the characters (the boy actor who played his son was great), the relationship between the boy and his father, and the better than average story lines. Even as a youngster, I thought the special rifle and the rapid firing at the hip were pretty bogus. I knew how to shoot a lever action rifle quickly and accurately, and I knew better than to flip the rifle in one hand while holding the lever.
I also liked Have Gun, Cheyenne, Bonanza, and Maverick. I often watched the other Western shows too. It was hard to avoid watching Westerns because they represented a very large percentage of the shows on TV.
But TV was new, wonderful, and magic in those days; so many people (especially kids) enjoyed watching nearly anything on TV.
There is also an unconfirmed rumor that before my family owned a TV, I received a complete Hopalong Cassidy outfit (hat, black shirt and pants) along with a gun and holster set for my 7th birthday. Say who?
As to those who are concerned with the misspelling of the word "cavalry", those of us who were in the cavalry find it annoying also
Blame it on over reliance on spell checkers, because a spell checker will not flag either spelling.