Is this a troll? No you don't need to care. Feel free to go live off roots and tubers in the forest. Or write some COBOL. Anything is justified if you're putting "interesting new ideas" in quotes.
I worked with PHP full-time for several years and energetically rationalized away the time I invested into building that expertise. I liked it, I was getting things done, it would help me get jobs in the future. Utter nonsense. What a waste of my life.
Eventually I snapped out of it. Turns out you can just move to places Silicon Valley, there are jobs at awesome companies working with the cool modern technologies. You don't need anybody's permission, just do it. Want to write Haskell/Go/Rust/Elixir/Clojure every day? Want to work with ML or robots or big data or whatever floats your boat? Just go do it. You don't need to sit there writing PHP as the world passes you by.
PHP is a backwater. People live there and tell themselves that it's fine, good as any place really, can't imagine anything better, probably wouldn't like it anyway. Or they just stop thinking about it.