In the same way (and for the same reason), simply retracting or deleting the comment serves little purpose. I see fit to attempt to clarify. The worst that can happen is that it will still yet attract downvotes. I have little to lose that I haven't already lost in failing to notice I had a comment receiving such negativity. At the very least, I am now aware that it is happening.
Yup, agreed that retracting/deleting the comment is similarly unlikely to achieve much.
Certainly, none of that activity is likely to clarify anything, since few people read comments after they've been downvoted below threshold. If anything, it's more likely confuse/obscure the record, as I mentioned.
Related: The Real End of Science
From the Economist.
I recommend reading the whole thing.