Currently the Bookmarks Toolbar option to "Only show on New Tab" is, depending on how you look at it, either not as useful as it could be or misleading.
It would be ideal to extend the option to encompass all new tabs, not just Firefox Home. I prefer new tabs to be a blank page, but I would like the Bookmarks Toolbar to appear and then disappear as this setting would seem to enable.
Failing that, it would be much less confusing to label the option "Only show on Firefox Home." This would avoid the confusion I and others (e.g., 1 and 2) have had trying to figure out why the option wasn't working.