I think you're missing the point of parent comment (or at least the point I'd be making) - it's not that those descriptions make it seem like the business will fail, it's that those descriptions make me not care whether or not they fail. I suspect the person you replied to, like me, isn't disappointed because they want to cheer on a possible unicorn but because they want to cheer on startups that are doing interesting things.
They were commenting about their personal feelings, as am I. Neither of us have stated we think YC will do badly because of it.
On the other hand, while I don't think it's bad enough for YC to suffer massively, they have presumably been helped in the past by having a strong following of techy people who just like YC and who assume that a startup funded by them is likely to be interesting. Will they lose that reputation, and if so will it matter to how successful they are? I've no idea, but it's not impossible.
