I attempted to make my previous comment neutral about the correctness of your claims; it was intended to be a refutation of tptacek's comment. And I apologize for oversimplifying your assertion to be about "coding in your spare time", which was inaccurate (although your original phrasing, "obsessive wretch", was sufficiently shitty that I thought I was doing you a favour by rephrasing, but I now agree that I didn't do the
correct rephrasing).
As for your claim itself, I think you have a good point, but you're a bit overextending its consequences, and ralfn's upthread response to you is right on.
I think you're totally right that diversity of opinion and interest is a super useful supplementary skill. And I strongly agree that a team needs to have that diversity on the product side to product useful products. And I agree that a team somewhat benefits from having not just a few product specialists who have that diversity; it's essential to have a few, but it's also helpful to have lots of people with diverse perspectives. And sure, being extremely tech focused (being an "obsessive wretch") is obviously inimical to that diversity. And yeah, there's some unreasonable glorification going on.
But I think there's also something reasonable about that glorification. Although deciding what to build is a huge part of the team's job, also building it is a huge part. Invariably the part that takes more person-hours, at least in a business large enough to have employees. And in my experience, the "obsessive wretches" actually do tend to be somewhat better at this part of the job. Not overwhelmingly better, but better. Not universally so, but as a tendency. That's just my observation from my medium-length career, and I accept your claim that you have different anecdata; if you have useful actual data I'm open to persuasion.
Moreover, very frequently in this industry we hire people who frankly are not currently knowledgeable enough to do the job we're hiring for, but we hire them anyway because it often works out, and we don't want to pay the asking price of the people who already know how to do the job we're hiring for. Call it good (it allows new entrants), call it bad (lots of wheel-reinvention, ageism, etc), but I allege that it's very common. So, who's going to learn faster? My bet is on the monomaniac; maybe this is unfounded. So, I think this is a rational reason to prefer the obsessives.
And I guess I should add that someone who has literally no other interests... okay, I'm with you. That person is likely to be a problem. But I will continue to favour people for whom outside study is one of their primary hobbies over people who do it a bit, and I'll continue to favour people who do it a bit over people who don't do it at all. And note that the example in TFA was not about someone with no other interests.... it was about one individual who did build a fibre-channel network over the weekend, and another individual who realized that they would never do so.