Yeah, you can get single speed cogs for Shimano, but they're not made by Shimano (their single speed cogs use a different system). And I'd be pretty surprised if anyone did em for Campy.

I'm thinking that whole 'throw the derailers in the bin' malarkey would tend to sidestep most Campy equipped bikes, which are vastly fewer in number, hence not enough demand for it.

Just do a SS with an 11s chain. Because the chain got so narrow, they had to put proper bushings in it instead of punching them in the plate (at least I know that was the case with Shimano chains), making them wear better than a lot of wider chains. Cog and ring wear is caused by chain wear, so it'll last just fine if you keep your chain clean and lubed.