Well, they're popular enough to have their own subreddit:
http://www.reddit.com/r/idleclickinggames/So let's talk about how to define a "game."
https://en.wikipedia.org/wiki/Game#DefinitionsPersonally, I like the Costikyan definition: "A game is a form of art in which participants, termed players, make decisions in order to manage resources through game tokens in the pursuit of a goal." By this definition, SMBC's
Sisyphus Quest and Progress Quest are not games. Cookie Clicker, however, is: it has a goal, requires decisions, and invovled resource management. And most other things termed games fit that definition, including JRPGs (where the goal is to complete the story, and the resources are characters, levels, and equipment), generalized RPGs (in which the goal is often nebulous or may be manifold: WOW and KoL do not have one specific goal in mind when you play them, but each person might choose a goal), and of course board games.
Cookie Clicker has goals in the same way WOW has goals. There's no storyline to complete, but collecting achievements, optimizing buildings to go faster than other people, figuring out how to gain minor advantages that will make cookies faster are goals that are just as valid as WOW goals like... collecting achievements, optimizing equipment to kill things faster than other people, and figuring out how to gain minor advantages that will gain you gold or prestige.
Or Dominion, where the goals are to collect achievements (winning), optimizing your deck to win faster, and figuring out how to gain minor advantages that will gain you VP faster than your opponents.
But here are some thing to compare with the question "Is Cookie Clicker a game?"
Is Tag a game? (My kids certainly think so)
Is War (the card game) a game? (Again, my 4-yr-old would say yes.)
Is War (the... war) a game?
Is a tabletop RPG a game?
Is a slot machine a game?
Is Farmville a game?
I think the answer to all of these is probably Yes.
Perhaps a better question to ask is "Do I enjoy this game?" I mean, the answer can most definitely be no. I certainly don't enjoy War (either type), but then I don't like Catan, or even multiplayer Dominion!
If you don't enjoy idle games like this, I totally wouldn't blame you! I think they can be amusing for a few days, at least the more intricate ones (see: CivClicker). But then I also played Mafia Wars for quite a while until I realized that hey, this is just clicking buttons optimally! Which evolved into idle games like Candy Box, and then Cookie Clicker.