Elemental Weapons Are Glitched?

No, the client shows the damage on your screen. Sunrise is correct. The damage applied to the mob is generated by the server and the client together.

The client data in the WZ files is intact, but that means nothing if Maplestory.exe is not programmed to read or interpret the value in the WZ file. If what you're suggesting is the current situation, people wearing the elemental staves and wands would be seeing much higher damage client-side than what is being applied on the server.

In short:

Client calculates
Server calculates and applies

So basically they're turned off in the client, even though the data is there.

I like the way I thought of it better because it still gives hope that Nexon didn't do this on purpose.