It's not reductive, it's misrepresentative. A puzzle game is only a puzzle game as long as coming up with the solution is the main task.
There are more than enough games where coming up with the right solution is not difficult, but performing it is.
Also the name puzzle game implies that there are designed puzzles. Any game where you have to make decisions in generated situations aren't puzzle games. For example if you take a specific chess situation and ask which move would lead to check mate in x moves then that's a chess puzzle. That doesn't make the game of chess itself a puzzle.