It’s true that sometimes bush beans might lean, if as you suggest the wind blows or (in my experience) the plant are too crowded. You could try a couple of things: mulch to give the plant stems more support. We’ve seen pencil-thin bamboo sticks attached to stems with tomato ties. You might put light rope/string snug (but not tight) to the stems of several plants in a row (tie the string to a stake at either end). If you can count on the wind coming every year, you might also try wind breaks—a wall of something that will allow wind to pass through but as a structure will break the force of it, such as lattice or a wattle fence.
It’s true that sometimes bush beans might lean, if as you suggest the wind blows or (in my experience) the plant are too crowded. You could try a couple of things: mulch to give the plant stems more support. We’ve seen pencil-thin bamboo sticks attached to stems with tomato ties. You might put light rope/string snug (but not tight) to the stems of several plants in a row (tie the string to a stake at either end). If you can count on the wind coming every year, you might also try wind breaks—a wall of something that will allow wind to pass through but as a structure will break the force of it, such as lattice or a wattle fence.