If someone says "No get out", it seems pretty clear that you should carefully think about what you're doing before posting again.
This isn't a system that's actually possible to meaningfully automate, and to do it with staff members alone would require a ridiculous amount of manpower and effort (since it'd require reading basically every thread for these kinds of posts), especially in active boards like Market.
"No staff or automated message notified me of such a situation" to me feels like you're just trying to take the lazy way out of reading the thread. I'm sorry, but we're unable to justify providing the manpower or efficient high accuracy computing systems to implement this request when the alternative is that we ask you to read the thread and think before posting.
Now, I'll admit, I don't know how many people actually get infracted for this sort of thing off the top of my head, but I'm pretty sure it's not a very large number. It doesn't seem like it's a hard thing to avoid, and it doesn't seem like it'd be difficult to tell in most cases when you should just leave something alone.