I don't know why it works the way it does, but I wouldn't want to be answering that dialog all day long so let's please not change it?

Two thoughts, though:

(1) You can undo closing a tab using any of these methods:

• right-click a different tab > Undo Close Tab
• Ctrl+Shift+t
• menu > Library > History > Recently closed tabs
• (menu bar) History > Recently closed tabs

Unless the site instructed Firefox not to cache the page, it should reload in the same state as where you left off (for example, scrolled down to the same point).

(2) There are add-ons to save work in progress on forms in case you close a tab accidentally and it restores empty. I haven't tried these, but have seen them mentioned many times:

• https://addons.mozilla.org/firefox/addon/textarea-cache/
• https://addons.mozilla.org/firefox/addon/form-history-control/

You can also find "Undo Close Tab" at the top of the "List all tabs" drop-down list. You can set browser.tabs.tabmanager.enabled = true on the about:config page to have this button visible permanently at the at the right end of the Tab bar.

You can open the about:config page via the location/address bar. You can click the button to "Accept the Risk and Continue".

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox