No you are not the only one. There are a lot of almost obsolete calibers out there that I love. I think my appreciation for those calibers comes from an appreciation of history? 7x57 was invented well over 100 years ago. It set the standard for all of the modern metallic cartridges, and in all that time no one has really come up with anything better. It can hold it's own against any modern caliber.
The .303 British was initially designed for black powder, and it still drops deer in their tracks.
Maybe I'm old fashioned but I don't believe in change just for the sake of change. I also believe in honoring achievement. Those calibers were were an achievement. I have no problem with change, but only for something better. I still haven't seen anything better than a lot of those old calibers.
My personal favorites:
30-06 (it's still popular but it has also been around 106 years)
And I'm reloading as well so that takes care of finding ammo. The only problem now is finding a rifle in good shape for some of those calibers.