Is it okay to forgo getters and setters for simple classes?

I'm making a very simple class to represent positions in 3D space.

Currently, I'm just letting the user access and modify the individual X, Y and Z values directly. In other words, they're public member variables.

template <typename NumericType = double>
struct Position
{
    NumericType X, Y, Z;

    // Constructors, operators and stuff...
};

The reasoning behind this is that, because NumericType is a template parameter, I can't rely on there being a decent way to check values for sanity. (How do I know the user won't want a position to be represented with negative values?) Therefore, there's no point in adding getters or setters to complicate the interface, and direct access should be favored for its brevity.

Pos.X = Pos.Y + Pos.Z; // Versus...
Pos.SetX(Pos.GetY() + Pos.GetZ());

Is this an okay exception to good practice? Will a (hypothetical) future maintainer of my code hunt me down and punch me in the face?