A quick comment - kumbaja and spacemonkey are both recent users of Calibre, if you go by their MR registration date. It's likely both are engaged in the time-consuming project of adding a pre-existing ebook collection into Calibre. When I was engaged in that project, I wrote a half dozen bits of code to make book entry and metadata fetching easier. Now my motivation is less. Like most other long-term users, all my old collection is entered, and the annoyances for adding the books I buy are far less annoying than when I was trying to add hundreds of books at a time.
Bottom line - it's not surprising that newer users have a bigger incentive to improve this part of the code than long-time users who have all of their library in good shape already.
Go to it boys - the part of the code you're looking at can definitely use some improvement. I look forward to seeing what you can come up with!