While you would probably be naive to expect courtesy on the Internet, there is no reason not to offer it.
It's no harder to write a courteous and constructive criticism than it is to write a harsh and mildly condescending one. The former can serve to foster creative discussion while the latter often kills it.
You earn respect and the courtesy of others falls out the other side. And even with all the trolls, anonymous bluntness and dens of iniquity that exist on the internet, there are plenty of ways to engage in positive or constructive feedback loops.
But if you've got a bad product (in this case a poorly executed and thought-out speculative redesign promotional piece) and you actually host it on a .com domain name for said product, it stands or falls on it's own merit.
Had this been a forum post or addressed to a design community with a culture of courteous discourse, I would decry the lack of respect and courtesy provided free expression, but as it stands, this was a cynical and misguided top level domain attempt that failed and should be called out as such.
No it's not. If you're silent only the praise is represented in the discussion. If five people like it and a hundred more hate it, I'd like to hear from the latter crowd as much as or more than the former.
It's no harder to write a courteous and constructive criticism than it is to write a harsh and mildly condescending one. The former can serve to foster creative discussion while the latter often kills it.