No, I actually think it's more complicated than that. I don't want to put words in their mouth, but if we go by your interpretation it really seems like they're coming to Hacker News to justify their use of slurs against people who do not appreciate it, which honestly just seems very unconvincing. If you really wanted to use a slur, you'd just use it…there's really no reason to come here to discuss it with people who are going to be overwhelmingly against what you are claiming you want to do.

Slurs are partially the actual word and partially the intent behind them. Once you get to know someone very well, it's typically the case that there is an understanding of no mutual malice between you and them. It is this context that "reclaiming" comes into the picture, because you have a shared perception of what the intent is. You might've heard of the "n-word pass"–it's kind of a meme, but before it was the concept was legitimate and the sentiment was that you're on good enough terms with someone that they know you're not trying to be malicious to them when you use it. It's a sign of trust, and to put it in vernacular, you can't
"transfer" a n-word pass because it's a product of your individual relationship.

Putting it a in slightly different context, I (jokingly, of course…) call my mom old and senile when she forgets something in a dumb way ("Where did I put my phone, I've searched the entire house…oh, it was right in front of me where I put it down seconds ago"). She knows I am not directing hatred towards her. With that said, just because I can call her old and senile doesn't mean you can do it, or that I can go do it to any middle-aged woman. But because both of us know each other, it's totally fine to say this among ourselves because it's shared language to us.

Now, with that in mind, I don't think the commenter actually was trying to justify being able to go around calling any person they saw a slur. How would they get in trouble for this? Well, I look different enough from my mom that our relationship isn't immediately evident all the time. If called her old and senile within earshot of someone else, it could definitely look like I was being a jerk if they weren't aware we knew each other beforehand. If I did it around other women of the same age, it could really cause issues. I would certainly not consider either of these a wise thing to do, but in my eyes these are really more a lack of tact or maybe misunderstanding of the context you're in rather than just a racist person wanting to be racist.

(You might be wondering why I would choose to use these words at all…I think the answer to that is really what reclamation is about. Nobody wants to be old and senile, but it's a thing that happens. My mom appreciates it that it's something we can joke about, and I think it helps her deal with it in a way. My understanding is that mutual use of slurs on friendly terms has a similar effect. There's a more extreme form of reclamation of "I think anyone can call me these words, even if I don't really know them, because I'm just really confident/proud of this" but I understand that's not for everyone, and it's definitely something that you can't just assume about people.)

Anyways, to circle back to the original topic, I don't even think my interpretation is a good faith interpretation, it just seems like the more likely interpretation, which is that the commenter has situations where the slurs is normalized and even encouraged by the people who they apply to. You seem to have interpreted this as "the commenter thinks that this means its OK to use them generally because they are racist" but this just doesn't seem to be the case to me. (And if it is…I definitely don't support that.) That's basically all I wanted to bring up.

(One final thing that has more to do with the sentiment of your comment rather than its content, which I think is solid: it seems like you wrote it from the perspective that I'm, at best, woefully misinformed and isolated from marginalized communities, and at worst some sort of closet bigot which you can discern from my comments. I'm a real human being with real empathy and real experience and real faults! I understand that this is a topic you're passionate about, perhaps maybe one you're tired of discussing, but you don't have to attack me to express your opinions on it. Even if it sounds like I'm disagreeing with you, I'm here to interact with new perspectives and learn from them. I only ask that you don't immediately dismiss me as close-minded, as doing so from the start only makes that more likely, rather than less.)