It's a good thing that someone created a backup-the-database utility as a plugin for WordPress, but it is very unfortunate that the author decided that "These are not exactly essential items to restore after a catastrophic failure".
I beg to disagree. Average WordPress sites tend to have over a hundred plugins. In case of failure, having to restore all this information can mean days of work. Many plugins tightly integrate with the posts absence of plugins tables may ultimately make the whole blog site unusable.
The excuse used by the author is "it's not uncommon for plugins to have tens of megabytes of data". Well, it's not uncommon for a blogs database to be hundreds or thousands of megabytes of data in size. So what?
Anyway, good work that you created the plugin, hopefully you decide to upgrade it one day to simply include the whole database and nothing less. Optionally you can always ask the user to exclude certain tables, if he so desires.