If an HN comment discusses an idea that could help in a personal software project, I would want to try my own implementation.
I don't mean go to the (possibly GPL'd) repo and just copy-paste everything.
At the same time, if it's my own project--even so a business plan, an investment strategy, or hardware schematic--attribute the credits, and go try it out.
The reason I'm on the fence with starting out proprietary or with the first commit including the LICENSE is that the latter is safest; and, it's easier to build with the intent to share from the start, then to clean it up later, even if it's never open-sourced.
But if it's exercise 7 of chapter 4 from a textbook, it's harder to predict a large, popular project grew out of that. Adding a license to everything seems overkill. Disciplined, but overkill.
I see a comment on HN from time to time about this. Someone building their own browser commenting on some implementation detail, but that's it (for example).
Because, once it's out there, yes--others can use it, or as you say, abuse it.
Do you have a (sanitized) example of how your thinking helped protect your software from being "exploited?"
(And here I mean the abuse you refer to.)