Linux is only about 30 years old, is it a fad like Git?
I disagree with what you are saying, Git was created by Linus Torvalds because there wasn't a tool that was good enough. Git worked, it overtook all other SCMs, because it's better. I don't see a big downside in learning other SCMs, but git is better then them by miles. If someone with 50+ years in the tech world said they were better at writing software than Linus Torvalds I'd ask for receipts. Didn't they create not 1 but 2 tools that are kicking ass?