To avoid loss of form input, there are several auto-save-to-localstorage solutions like http://garlicjs.org/. Just add data-persist="garlic" to the form tag and everything is saved until successfully submitted.
As a developer it's annoying because it slows down testing - again edge case, but I've seen it before, and it annoyed me.
If it was the standard behaviour and all controls were sensitive to it, that would probably be different.
There's also the security aspect to keep in mind. So now when someone comes back to a page on your machine, might they see something you didn't want them to see?
https://addons.mozilla.org/en-US/firefox/addon/lazarus-form-...