I'm a bit confused on just what is being called an "installer".
Are we talking about Windows Operating System KBxx hotfixes only? I kinda have to assume that we are.
If we are talking about something like Office 2000, XP, 2003, 2007, or 2010 (all of which have their own KBxx list of hotfixes), then alternate methods of DEPLOYMENT (versus "installing") is really nothing new. Heck, I've been copy-pasting my Microsoft Office "folder structure" from one machine to another (ie, when the first machine is dying and I'm about to send it to Silicon Heaven) to the replacement machine, exporting some registry keys, importing to the replacement machine, and everything works perfectly fine and I've been doing that for 20 years. Works great for Excel, Word, and PowerPoint. Outlook is a different beast altogether, can be done, but not as easy. Migrating / "deploying" from one machine to another has never really technically required a "re-install". Just copy-paste and export-import. Done. And yeah, it's FASTER than "installing".