Is it bad to finish an arguemenative paper with ...so why not?
I'm pretty sure that may soften the point you're trying to make, so unless the rest of your paper kind of goes along the same lines, I would try to find some other way to end it. It kind of sounds like you don't care much about your topic or are indifferent and it may take away some ethos from your essay.
Yeah i assumed it was a horrible way of ended a paper i just wanted to give my reader more to think about. I corrected it though so thanks.
...so why not?
. . .
If its argumentative, then you don't want them to think. You want them to know you are right, so finish it in a way that further proves your point.