Yeah, it's not so much a diagnosis of this particular case as it is a pithy vignette on the expectations people have of Google and the reasonableness thereof.
But again, you are acting as if there is a definitive answer to the query [secure email] (which is one mentioned at the top of the article, and what inspired my comment). Among the results - after a healthy block of ads (and since this is an article from 2016, Protonmail) - I saw a page about setting up Mozilla Thunderbird, Hushmail, and numerous blogs/articles about eg "The 5 Best Secure Email Solutions". This is not to say there wasn't a problem back in 2016; I just mean that on a broad query like [secure email] with probably dozens or hundreds of good results, not seeing one in particular is not really a red flag that something is wrong to me, the way not seeing ProtonMail for the query [protonmail] would be.
Meanwhile, people immediately jump in with accusations of "Perfidy!", assuming that Google must have Done Something, and simultaneous with that demands that Google Do Something, and complaints that it is hard to get Google to Do Something whenever you find such an obvious problem.
And from the inside, you just sort of have to laugh-cry whenever this comes up, because (despite some fraction of techies wanting Google to act like an SQL query on the web) you are intimately familiar with the legendary Algorithm as an immense, constantly mutating series of heuristics running on inputs which (being from the web) are frequently garbage. You debug queries constantly, and while very rarely there is an obvious, correctable data problem or bug, you are really working to identify "loss patterns", large numbers of queries that are wrong in the same way for the same reasons. Your job as a ranking engineer is to then try to correct these loss patterns, knowing that when you do you'll be creating new, smaller loss patterns. Smaller because you spend years of your life evaluating your changes to make sure they are creating fewer problems than they fix.
And though you spend all your days carrying baskets of pebbles from the valley of losses to the mountaintop of good answers people crowd around you to point at a particular pebble lying on the ground, declare it the most important pebble and demand you put down your basket and carry it to the top of the mountain first, cradled gently in both hands. And each person in the crowd points at a different pebble, demanding the same thing.
(No, really, it's a very rewarding job with challenging work and they treat you pretty good here; if you're interested in the problem, I encourage you to apply. There are a lot of pebbles left.)