Amazon search: Super Smash Bros Melee (this one's always a kicker. I gotta replace mine soon because the disc isn't reading sometimes)
Amazon search: RCA or any brand fat TV
Amazon search: Nintendo Gamecube
Now add the prices.
Do you assume every tournament host has access to the money to furnish a room with these essentials for a Melee tournament? No. Go to any tournament (or at least local ones from my experiences), and they'll usually ask that players bring in their own hardware to provide enough places to play. Add a simple registry with labels and boom, there goes your worry of theft. Chances are if a player is interested in the tournament scene, they're probably going to own a Wii U and a copy of this game. Shouldn't be too hard to find a couple of people willing to donate their hardware for the day.
Also, LAN connection is really simple. Nintendo even has an
official adapter out there dating back to the Wii that they recommend for faster online play.
Nintendo's idea is actually better though from a competitive standpoint. Keep in mind that the human brain can only process so much. By splitting the screen and have each split display a different perspective, you're diverting attention from your side. You can say this isn't a problem by just focusing on our side, but human vision just doesn't work like that due to how wide our viewpoint is. Having just one screen focusing on just your perspective allows the competitor to take in all the information they can process without unneeded distractions.