While this shows admirable courtesy, I do feel that extreme prejudice against crapware toolbars is perfectly justified. So, I prefer to take the "shoot first, ask questions later" approach here.
You mean there could be people who actually want the toolbars?
I know someone who likes the Yahoo! toolbar. (Or "liked", I guess. I don't know if it's around anymore.)
Lots of people apparently liked the Google Toolbar for Firefox (even though it was installed along with other software, hijacked your bookmarks, and generally behaved pretty much like every other malware toolbar out there). More to the point, since it hijacked your bookmarks, if you uninstalled the toolbar all your bookmarks disappeared.
I always back up the bookmarks before doing any maintenance on someone else's browser.
Last I checked, it hijacked the normal browser bookmark stuff, so backing up the browser's bookmarks wouldn't back up what the user saw.