Toward those with a problem, it is possible to feel some empathy as their illness negatively impacts their lives while still recognizing the illness as an objective fact. Your analysis that those not showing some minimal level of empathy are mean spirited and stupid sounds more or less correct to me although its a matter of degree which makes it messily analog and complicated.
As for commentary about lost memories and such, in the long run we're all lost. Live your life to live, not to be documented and preserved. You're a person not a wikipedia article. I don't think you'd like most eastern philosophical outlooks on life; but we don't have to all agree with each other, merely be civil enough in our near direct opposition. Historically humans have done worse.
I would disagree with the ignorant, useless commentary in that most people know (of) someone with a hoarding problem and here on HN we know all about complicated technical rituals. As for the useless thats hard to parse, there seems little point in referencing a hoarding support URL in a locale where we all pretty much know how to google. And people who are sick usually already know so mentioning it isn't helping, as you correctly mention.
Overall a mixed bag, 7.0/10.0 as a comment about half the wide ranging comments were good and/or half good, some not so good. Well written from a literary standpoint although some logical argument issues behind the first glance.
On a broader scale I think its interesting to consider hoarding in the digital age; not seen much on that. Most of the diagnostic criteria from meatspace should transition pretty smoothly into tech; is the behavior negatively impacting the victim, and so on.
I don't think the cure for digital hoarding will be bigger storage or more outlandish technical schemes; I suspect a lot of people agree with me; this is probably the root of the "backlash" rather than some inherent hatred of victims. The dude in the article is doing the exact wrong thing to fix his fundamental problem with outlook on life, therefore intense backlash. I wish him well, even if I think he's going in the exact wrong direction to actually fix the problem.