When I was an engineer I used to think this, but now that I'm a manager, I'm not so sure...
If you want to maximize your impact, and make the biggest contribution possible to your company, then yeah, sure, it's absolutely the best use of your time.
But a lot of engineers are trying to contribute to the company in ways that are mutually beneficial to them, and the way that a lot of companies set up interviewing is not. It's a thankless job that takes time away from things that can actually be put a performance review, so only the more selfless engineers will do it.
The article reads a bit like manager-to-engineer advice, but the advice to managers would be: keep track of who is helping out with interviewing, and who is interviewing well, and reward them for it.