This is just flat out wrong. Math uses root -1 right? It's a very, very important part of math. Try to find that in reality.
And the physicist uses
i, all the time. It is integral (pun intended) to Relativity and Quantum Mechanics.
However, when we end up with a result that says something is 5
i meters long, we know we've probably screwed up somewhere. We even have a term for such things - "non-physical result".
Part of what you're talking about is a simple fact of human cognition. We humans don't actually *think* in mathematics very well. Unless you're Stephen Hawking, you don't generally do partial differentials or matrix calculus in your head. Taking the math, interpreting it as a physical result, as if it were real, allows us to apply more intuition in a thought process.
And, to speak about some of the results to laymen, it is pretty much required, because laymen just don't have the math.
But, in the end, we re talking about two fundamentally different processes here:
A physicist looks at the real world, makes a mathematical model of it, and sees what comes out - we start with reality, so it isn't so weird that we then try to relate the math back to reality.
A gamer is looking at a math, accepting that it is a model of a world, and trying to infer the world from it. The problem is that a gamer is not often starting from a well-defined "reality" to start with. Sometimes (say, with a game designed to model a specific work of fiction) there's a "reality" to refer to, but we lose that when the system is more generic.