Nah, that's not true. Ranger is one of the classes that has a direct equivalent in the real world. Daniel Boone, Kit Carson, Davy Crockett, Lewis & Clarke, and so on are all rangers. They same could be said for most frontier bounty hunters, marshals or sheriffs. Pioneers, frontierspeople, woodspeople, mountaineers. Even people like Teddy Roosevelt might qualify.
They were, in their time, doing exactly what 1e rangers did. Bringing "civilization" to the "wilderness." We certainly don't glorify their interactions with the indigenous populations anymore, but they were self-sufficient, knowledgeable explorers doing what they thought was best to expand their culture into new territory or to protect it from skirmishing invaders, natural or human.
We even have careers today where the actual job title is ranger:
Park Ranger. The job itself is even more in line with what the 5e ranger class description provides. Incidentally, that Wikipedia article provides an excellent history of the term "ranger".