The Triforce is a rather mysterious and, frankly, unknown object within the Zelda universe and quotes from one game seem to contradict another and so on. Here's my overall thoughts about the Triforce and the question at hand:
So we know that the Triforce was left behind by the Golden Goddesses - all mighty beings who's power is hard to fathom. The Triforce is basically an object that holds an essence of the three Goddesses: Power, Wisdom, and Courage. It's these three virtues that make up the balance of power in Hyrule and this must be kept in tact to maintain order. So the Triforce isn't really one to distinguish between good or evil as that's subjective and I doubt the Triforce, even being all knowing, would be biased towards one side. Of course it's clear to us which side is evil and which side is good, but as I said, the Triforce simply cannot lean towards one side. If the Triforce was only made for good, then good and evil would not exist - these two go hand in hand as they counteract each other, think Yin and Yang, you can't have one without the other.
What we know is that, like I said in the previous paragraph, the Triforce is a combination of three virtues that must stay as one for order to exist. I would like tothink that the Triforce was left, not to keep out evil, but to just maintain that order I was talking about. You wouldn't wish on the Triforce unless you had to; however if that order turns into chaos then that's where the golden relic's power truly comes into play.
As well all know, the terms for one to wield the full Triforce is a balanced heart. Remember balanced isn't good or bad; it's power, wisdom, and courage. So this could potentially mean that, yes, evil could use the Triforce too. If you think about it, the Goddesses were the only known creators and thus they're the ones who created both good and evil. You could probably turn the situation around and look at this from evil's point of view. Evil only exists to antagonise good, if there was no good then there would be no wars, right? So evil could potentially use the Triforce to get rid of the "good" forces and then that would bring order back to Hyrule.