You don’t want your thesis statement to be a question. You don’t want to pose hypothetical questions to readers. Those elements are hallmarks of sophomoric naivety (sorry to anyone who does this – welcome to your wakeup call nonetheless). I won’t say this statement is absolute or exclusive, as some people can pull it off, and some topics warrant such a style.
But by and large, it’s simply not a collegiate-grade maneuver that will impress many people. Strength in your voice goes a long way to the impact and quality of an essay, keeping that strength of voice throughout the paper is tough, and you don’t want to lose any of it. But with an intro like that, you’re pretty much embracing a weaker tone from the get-go.
It also goes back to title-writing and thesis statement writing anyway, you haven’t formed a strong argument, point or built a unique platform with your posed question, even if you reworded it to a statement. Dig a little deeper in your topic and draw the reader in while making your stance. You’ll have to take a side on this one anyway, it sounds like… so take one from the beginning if that’s within the scope of the assignment.
You can still argue both sides, even when you get behind one of them (in fact, in an argumentative paper, you are obliged to present both sides).
Anyway, sounds like you should find a strong, interesting point within the controversy you’re studying, go more for the details therein and less on the generic subject and let a new thesis statement (not question) flow out of the more honed-in topic. Good luck!