So they open a store here for a bit, sell hamburgers, protect their trademark, then leave?

Why is this such a bad thing?

It's bad because local Australian businesses can't use similar names to "In-N-Out" during the other 1000 days without getting sued for trademark infringement. Example from the featured article:

> In 2020, a Sydney burger chain formerly known as “Down N’ Out” lost an appeal to flip a court decision that forced it to stop using its name and hand over its signs and promotional materials after being sued by In-N-Out Burger for trademark infringement in 2017.

The original title is:

> In-N-Out Australia Popups Are Back, Just So The Chain Can Keep Suing Over Trademarks