Is it...

The amount of confusion from this riddle?
My appetite?
How much wood a woodchuck would chuck if a woodchuck could chuck wood?
CraftyMynes' reputation?
My inability to solve this riddle?

@NutjobBob @Synchronous
That's a neat way to do it, it's good to know that it's possible. However, any guardians added to the notElder objective that are unloaded when the kill command runs will not be killed, and will not be removed from the objective, it'll keep adding more guardians that may never be removed, which might be a problem.

I don't think it should be a problem; the guardians would despawn prior to being unloaded (depending on render distance). Nonetheless, if this is a problem, /scoreboard objectives add notElder dummy could be placed in an always on repeating command block, and after the other ones /scoreboard objectives remove notElder could be placed in another always on repeating command block (or chained in an always on chain command block, depending on how the clearing system is set up). This would constantly create and remove the notElder objective, removing it from all guardians--loaded and unloaded--and adding it back only to the loaded ones.

@NutjobBob I'm fairly sure that there is no way to kill guardians and not elder guardians.

Run this once: /scoreboard objectives add notElder dummy
Put this into an always on repeating command block: /scoreboard players set @e[type=Guardian] notElder 1 {Elder:0b}
And then put this in whatever apparatus is connected to the clearing system: /kill @e[type=Guardian,score_notElder_min=1]

I do agree that elder guardians should be left alive and guardians should be killed.

Here's a nicely organized post for you to bookmark or keep in mind.

Voting links:
http://minecraft-server-list.com/server/262180/vote/
http://minecraft-mp.com/server/69823/vote/

Page with both voting sites embedded:
http://votemc.github.io/#g6d696e6563726166742d7365727665722d6c6973742e636f6d2f7365727665722f3236323138302f766f74652fg6d696e6563726166742d6d702e636f6d2f7365727665722f36393832332f766f74652f