I never understood the appeal of physical coins, especially when people were paying a big premium for them, but I guess now they turned out to be a great investment as they've been selling for an even bigger premium. It's nuts.
I think the main appeal is as memorabilia, which appeals to collectors.
The ability to hold a bitcoin in a physical form is appealing, although concept of a physical bitcoin is an oxymoron. Perhaps that is part of the appeal.
In their current state, they aren't very feasible as a currency. That might change some day.