Dear Stéphane,
Your essay is brief, well argued and to the point. You give good arguments for the idea that we discover mathematics. I like the way you put it:
"Mathematicians would then be a bit like explorers trying to reach the top of a pristine mountain. Each uses a different way, meets different obstacles, develops different tools; but all arrive at the same summit and discover the same view."
Your essay focuses on the relationship between known (or potentially known) mathematics and the observable (or potentially observable) physical universe, and it is no surprise that there is no real mystery to the fact that they are quite compatible. You may be interested in reading the comment Julian Barbour left on the page of Derek K. Wise's essay: he essentially presents the same argument that our brains evolved within our universe, which explains why the mathematics naturally developed by our brains matches the physics of our universe.
Strangely, your fine essay has been nearly forgotten so far in the competition, and I hope bumping it higher in the community ratings will make it more noticeable. Good luck!
Marc
P.S. In my essay, I tackle a different and more ambitious issue, the question of the relationship between "All of Mathematics" and "All of Physics", which necessarily takes me on a more philosophical path.