Wow, I'd love to know the story behind that. My guesses (A) No one cares enough to add it (B) some core maintainer is actively hostile to the idea (maybe someone deleted their bug report once and they've been getting revenge on the world ever since) or (C) the codebase is too fucked up for anyone to figure out how to add a delete button.
Industry-wide institutionalised hoarding disorder that condemns us all to live atop the ever-expanding junk heap of the past, with the hoarder's justification "might come in useful one day". And that workaround is an accidental bug.
A world where big important decisions made in person go completely undocumented, yet weeks of bickering and bikeshedding over nothing are kept forever.
or a report, no you need to create a bogus product (which is not a single click either), move the report there, and then delete the whole product.
It's really a bit a PITA to use, the search is IMO quite good though.