But many others may disagree with you, and decide to invest that 10 years in really learning it. There is no problem with this. Just wait until you invest ten

But many others may disagree with you, and decide to invest that 10 years in really learning it. There is no problem with this. Just wait until you invest ten years of your life to master a language, only for everyone else to move on to the next new trend, with you stuck holding the bag. AngularJS, Rust, and node.js, is it? I can't wait to ask you how you're feeling about all that time you invested into all of those, when all the kids move on to something else and they're no longer popular, for no reason other than the newcomers' ignorance, or because something shinier came along, but didn't actually add any value, just re-implemented the old thing in a worse way. We can then have a discussion about how you're feeling, having wasted a decade or more of your life away on what will then be perceived irrelevant. That's of course under the (optimistic) assumption that HN is still going to be popular in ten years...