Indeed. You can't fix stupid titles. But if there is a real issue with the title- it's misleading, sexist, or what-have-you, don't fix the title. Write your opinions as a comment or a separate blog post.
The point is- the title isn't important enough to worry about- content is.
But unless you read every article that hits the front page, titles are important.
Titles are how I decide which articles to read, and often the original title doesn't explain why the article should/might be considered interesting by the HN audience.
Well, actually, the guidelines ask us to submit the original. But you can submit the original and link to your blog in the comments.