We wouldn't have a game if everything than CAN be exploited in a singleplayer game got changed.
It is necessary for players to begin understanding that even though something CAN be exploited it doesn't mean it will be.
Of course you didn't explain what you're referring to so this may be way off topic. But it does sound a lot like the complaints over the "respec" mirror, yes you CAN exploit it, if you don't like it, just don't, it's a single player game.
There are absolutely no effects on your game if someone else uses this "exploit" on their game (I also don't use them, I think the difficulty is already flawed enough as is, but that's another subject entirely).
Again, without a propper explanation of the issue it is quite possible that I'm being unfair here, but, if the problem lies somewhere along the lines of "the player can go way off the normal path to get an unfair advantage" (like infinite bodyguard hiring with a respec on thievery) then it is not an issue, unless you make it an issue on your game, but at that point it's not the developer's fault.
