It's not possible to simply say a particular hand isn't profitable to play pre flop, because there's a million ways to play the hand post flop. Savy is right, it's about what's most +ev. 23o would be an unprofitable hand to call... unless we have specific reads that villain is cbet/folding waaaay too much, perhaps meaning we can call and then raise any flop.

As for exploitation, well an unfortunate aspect of poker is that if you are trying to exploit, you yourself become exploitable. This is why we're constantly adjusting.

These kind of excerises are excellent for learning about our own range, but the simple answer to your question, ie what range do we 3bet with, depends a great deal on the dynamics up to this point. We have 237 hands on this guy, but what happened last time he raised our blind? What happened last time he was 3bet? Do we think he's adjusting? Do we think he thinks we're adjusting? There's so much more to this than simply assigning ourselves a range. I believe your 3bet range should be dynamic, not static.