Sure, so let's start simple.
Wikipedia's definition is not perfect, and you are trying to hang your hat on a technicality that does not exist.
Your argument is about the domain name itself rather than the content.
He has not named a product after another product. He does not have to call it "thestatusofvariousphotosharingsites.com".
It is okay to name your website "walmartsucks" and talk about how much walmart sucks (though it's not okay to do that and then try to extort money from walmart, as one guy did).
His website is about tumblr, the product. he can name it after tumblr, the product, as long as he does so in a way that confuses no one, and satisfies a bunch of other factors. Nobody is visiting his site and thinking "oh shit where are my photos". If there was some possibility of confusion, or if his website directed people to instagram, or any of a few other things (like tumblr was planning on expanding into what google tells me is a pretty competitive "is tumblr down" market), you may have a point. But it doesn't do any of this. It simply gives people the status of tumblr. He makes no money, he offers no non-substantiated facts, he dilutes no trademark.
In this way, it isn't even an arguable case like "walmartsucks", because the domain name is literally a description of itself.
Yes, it would be a lot clearer if he added disclaimers, but that's again, completely irrelevant to whether it's necessary or required.
"Neither Ford nor Consumer Reports publish an unidentified 'do toyotas break down a lot' magazine or website so this seems somewhat different."
It isn't. It is, as they say, a "distinction without a difference".
and you are trying to hang your hat on a technicality that does not exist.
God, no, I'm just running with the thing and I'm appreciative of you taking the time to respond in detail.
Your argument is about the domain name itself rather than the content.
That's exactly right. That and some woolly idea that that the notion of 'confusion' figures in some important way in trademark law.
So when you brought up 'nominative use' I thought doesn't the whole confusion thing come up? Does it come before or after the test for nominative use?
If there was some possibility of confusion
To me, it seems at least conceivable that that's confusing. Maybe tumblr runs such a service, as a status indicator. It is, as you said, a statement of fact - you know, if you can't get to tumblr, please check istumblrdown and we'll tell you what's going on. So I have a harder time getting my head around the idea that istumblrdown is obviously unaffiliated with tumblr the way walmartsucks isn't affiliated with walmart. The EFF page you linked talks about confusion as well and I think that's, err, the source of my confusion.
Your argument is about the domain name itself rather than the content. He has not named a product after another product. He does not have to call it "thestatusofvariousphotosharingsites.com". It is okay to name your website "walmartsucks" and talk about how much walmart sucks (though it's not okay to do that and then try to extort money from walmart, as one guy did). His website is about tumblr, the product. he can name it after tumblr, the product, as long as he does so in a way that confuses no one, and satisfies a bunch of other factors. Nobody is visiting his site and thinking "oh shit where are my photos". If there was some possibility of confusion, or if his website directed people to instagram, or any of a few other things (like tumblr was planning on expanding into what google tells me is a pretty competitive "is tumblr down" market), you may have a point. But it doesn't do any of this. It simply gives people the status of tumblr. He makes no money, he offers no non-substantiated facts, he dilutes no trademark. In this way, it isn't even an arguable case like "walmartsucks", because the domain name is literally a description of itself.
Yes, it would be a lot clearer if he added disclaimers, but that's again, completely irrelevant to whether it's necessary or required.
"Neither Ford nor Consumer Reports publish an unidentified 'do toyotas break down a lot' magazine or website so this seems somewhat different."
It isn't. It is, as they say, a "distinction without a difference".
The EFF has a page about this, btw: https://www.eff.org/issues/bloggers/legal/liability/IP
search for "Can I use a trademark in my blog's name or in the title of a blog post?"