It's not accurate to imagine that HN (or any sufficiently large internet forum) could have a "serious discussion of pros and cons" of imprisoning rape victims. For every user who might entertain that as a disembodied thought experiment there are countless more who will react with physical aversion, entirely understandably. As for "productive and curious", https://news.ycombinator.com/item?id=26501428 (or much worse) is the statistical outcome of a provocation like that.