Why not call your favorite wine "jar of horse piss"? Wont it sell equally well on its merit?

Because that is what the "feta-like" phrasing is doing in consumer's minds. Put the same feta side by side, where one is labeled "DOCG greek feta" or whatever, and the other is called "feta-like cheese", and the greek feta will outsell the other 100% of the time.

Yes, but certain things are no more owned by one country or region than the world due to the dispersive nature of culture. If a Greek moves to the US and starts making feta there (say, even with the same milk fermenting bacteria), it's still feta, unless it's truly believed that national character imparts flavor. What then becomes the difference if a Greek teaches another how to make feta and they do it elsewhere? Or if someone replicates it on their own? A chef's national identity does not a good dish make

If an employee of Nike, at whatever level, leaves the company to make their own shoes, they can no longer use the Nike trademark to market them.

There's a difference here. Most people don't make shoes in their kitchen. Most people do produce foods and pick up recipes from regions proximal and distant. It's one of the inherent motivators of travel and commerce for centuries.

Further, Feta, for instance, has existed for hundreds of years. It's no more owned by one person than Greeks themselves at this point. It's spread over the world, in the same way as Parmesan, or other cheeses and foods. The supposition that this is exactly like trademark law is absurd and mechanical.

The exact same argument can be made for nike shoes.

Discounting a whole lot of nuance, you apparently can use Nike shoes in any argument.