Are there downsides to quitting the Finder after enabling the menu item to quit it? In Why is the Finder app always open?, it was noted that you could add a Quit menu item to the Finder via a Terminal command, but the comments and one of the answers seemed to indicate that this was a bad idea and should be avoided unless you had a could reason. Why is this this? Does this prevent the system from working correctly?

I myself have enabled the Quit menu item in the Finder (via TinkerTool, rather than the command line) and find it useful for presentations where I don't want to show everybody my messy desktop or any open windows. I've also quit when I thought that I could use the extra RAM (like heavy Photoshop editing), although to be honest I don't know if that's effective. Are there any negative consequences that could result if I kept doing this?
Finder is the application Mac uses to well... find files.

It should be perfectly fine so long as you do not run anything that specifically calls finder, i.e. AppleScript. You'll also (obviously) lose all your open Finder windows. 

I completely understand quitting for presentations, but there should not be much of a performance improvement if you quit Finder.

So, no, it should not be a problem, just note that apps that call on Finder should open Finder for you, so you'll need to quit it again. 

Thanks to @user3439894 for catching me on something I said wrong.