I think this is exactly the right place to bring this question up occasionally, we're not talking about every other thread here - these conversations are rather rare. They give an idea and hint to people who may be starting to consider whether they are gambling too much, or they might pick up a useful tip on how to gain back control in that scenario. They are perfectly harmless in that sense and offer a more rounded experience to the forum, it would be stranger if they were missing entirely. If you are not interested in the topic or feel like it doesn't apply to you, then simply avoid such discussions - it's not harming you at all and it's weird you'd even find them so strangely offensive or act like they are super common.
I totally agree with you, I don't really find a lot of topics or threads related to gambling addiction, though we can find people advising others to try and avoid getting addicted to gambling because that is absolutely not harmless for anyone, and I find that being a good thing since if we can talk someone out of their way to addiction, it's a noble deed as the addiction can ruin their life forever and we might prevent that from happening by stopping them.
And even if a topic or a post isn't specifically targeting a person directly, it can still be the reason for someone to learn something from it and change their way of gambling, they may become more responsible and disciplined. So in my opinion, these discussions do contribute a lot and they should stay.