It's copying a subgenre not cloning.

Clone need not be such a dirty word. There's a difference between a game trying to capitalize on a successful model and a game that simply steals from another. Games like Mole Kart and The Great Giana Sisters are quite clearly infringing on intellectual property. But games like Hexen and The Simpsons: Hit & Run, while clones of popular and successful games, manage to create something unique and something worth playing.

That being said, Playstation All-Stars and LittleBigPlanet Karting are most definitely clones.

apparently its a clone if a game is in the same genre

A game that just copies another game's entire formula without adding anything new is what I'd consider a clone.
Lots of games are heavily inspired by other games but that doesn't necessarily make them clones.

so take completely change the core dyamic of the gameplay.

you know it makes sense now.  if you switched all the walking in uncharted and replaced it will vehicles and switched all the guns for shells you'd have a mario kart clone...

Farmville is a terrible version of Sim Farm.

when it looks and plays similar. Simple enough criteria I guess.

Your post was clearly just made as damage control out of your fear that your main argument for putting down these games might be exposed as flawed. Hence why you try to pass off the perfectly fair questiion as worthless instead of trying to provide an intelligent answer or counter argument. If you believe the word "clone" is fair to use in regards to the games in question, then i suggest you follow in the footsteps of JI99saw, Alelyn and others who have taken the effort to explain their points of view in clear and respectable ways. 

Anyway back on topic. The problem I have with the "If you can find similarities between them" rule is that it is too open ended. For example I can find simlarities between Pikmin and Age of Empires. However it would be very naive of me to refer to Pikmin as a clone. Perhaps a better statement would be "If you can see more similarities than differences, then one of them is a clone"?

This definition is way to vague. You could say Forza is a clon of GT according to this definition. IMHO, it doesn't needs to be just similar, it needs to take lots of elements, looks and feelings from the original.

I think PSABR is a clone. But LBPK adds enough content that could be considered a game of its own...

Depends on the genre. With car games, the look and tracks are set in stone. Cant change the design of a car. But fictional games like Smash Bros and Battle Royale are purely up to the design of the game developer.