Well, do you allow account deletions then? It should be supported under GDPR. We discuss this about other tech companies all the time here on HN. I never realized this is not possible on HN.
GDPR does not give a right of account deletions; it gives a right to delete personal data, and even that is caveated, and comments you leave on a site like this as not really "personal data" in the way that's intended with the GDPR.
Besides that, for the GDPR to be in effect you'd have to be an EU resident and the OP is not.