It is a fine round, as is the 6.5x55, 7.65x53, and 8x57. A previous poster touched on it, it's not American. The time frame when it (these) were cutting edge cartridges, other than an elite cadre of well heeled individuals, most hunting rifles in the US were a lever action or a surplus Krag. Some Spanish/US war bolt rifles and rolling blocks were available in this caliber between 1900 and 1920's, and it saw some use by rank and file sportsmen. The military of the US absolutely was interested in it's performance, but were set on long, heavy and round.30 caliber tooling and bullets, and didn't really take an interest in the long range capabilities of a pointy bullet at high velocity until Germany did.
After WWI, 8x57 and 30-06 bolt rifles were common on the surplus market and easily converted into inexpensive sporting rifles. Soon after followed the .270 Win, and a few high velocity lever/semi auto rounds that filled most niches in American style hunting. Optics really hadn't gained enough universal acceptance to realize the LR potential of a sleek 7mm bullet. Why get a 7x57 when you could get a good old Winchester 270 or Savage .22 HP, .250 or .300? Maybe a .256 Newton or 6mm LEE or 280 Ross if you really wanted something swanky!
The rest is history. It's always been a niche cartridge here. Popular in Europe still today.