(Topic, and title phrasing, suggested by odditycollector)
I saw it said once that Tumblr is a party. I think that's a fair characterization. I can see it as a sort of image host, and a friendlier one than the old image hosts with their grey interfaces and irritating ads. Taken as these things, Tumblr is fine.
But for a social community site, it is (as is Twitter, as is Facebook) a step backwards from the journal site model of LiveJournal/Dreamwidth.
Now, I think there are parts of Tumblr that "don't make sense" to an old journal-site user, but do make sense on their own terms. I want to, for the most part, leave aside things that are annoying about Tumblr but make some kind of sense, which should leave only a few things:
One: If I “<3”/like/heart a response to something, that is counted the same as hearting the original post as far as the original poster knows (or, for that matter, anyone outside the specific chain of respondents in the response I hearted). That’s confusing.
Further, it at least used to be the case that one could not “<3” something if the original post was no longer there—as I recall. I’ve not tested that lately.
Two: In theory, I could rewrite this entire post into a rabid denunciation of the Irish race after y’all “like” it, and it would still count as you “liking” it. Oy.
Three: You can have 153,546 notes on a post, most of which are noise, and not be able to find many of the actual comments, if any. You can fold a Disqus thread in if you are inclined, and some people do, but Tumblr itself is, well, shaped like itself. I’ve grown to like its strange forking threads, but they’re not organizedly archived to be tracked down, they’re wild moments of a long party that still leaves scrambled tracks on the servers. So once a thread gets big enough, fuggeddaboudit.
Related: I have known a few users to try to use Tumblr as a blog for general readership or as a webcomic host. It mostly worked, too—for other Tumblr users. Unless they added Disqus, outsiders found the inability to comment annoying.
Four: The biggest problem I have may be this: On Dreamwidth or LiveJournal, I can organize the blogs I follow into filtered categories. So if I want to just look at my real-life friends, or just communities, or just fans of Wonder Woman, I can (with a little work) set up filters to do that. Of the new models of social media, I think only Google+ lets me do that with a single account.
Tumblr lets me run multiple blogs, thus splitting my output for other’s consumption, and organize my own posts with tags, but doesn’t let me organize my friends’ feeds. So I end up doing a lot of unfriending just to be able to keep up. And don’t you have that one friend who overspams but you can’t quite bring yourself to get rid of, so you end up reading a lot of their reblogs and reblogging them yourself until you feel like an echo? That’s a thing here.
Five: I almost hate to add this, because I like the flexibility of design in Tumblr themes. But it’s a journalish site, not a GeoCities page, so here goes:
A lot of Tumblr
skins themes don’t have date stamps. I once had reason to try to explain that a depressed friend’s suicide note on Tumblr was actually posted in the previous few hours, and I remembered seeing it new in that timeframe on my dashboard, and if I logged into my dashboard and found the post there, I could read the date that way. But no way on the blog itself to confirm. And I was in any case talking to a someone in another state over the phone, so they couldn’t really have without making an account, which was too much trouble. “It was in the last two hours, I remember, just trust me.”
Six: No screens! Really? I can “hide” a post (even from myself), put down the URL somewhere and then send you the URL so you (and anyone with the URL) can see it. If I do, it will not show up in anyone’s dashboard; not mine, not my best friend's. So keeping track of those is hard. But Tumblr can’t have something screened so only certain people can see it, and yet they will see it automatically—a core function of LJ, which LJ does easily.
Anyway, lately, I am realizing that LJ had a really good basic design, and more recent stuff has been inferior in the interest of being different. An old acquaintance has lately returned to LJ after deciding that Facebook required too much personal vagueness.
Wow. I thought I’d have two or three things. I came up with six!
But I do like Tumblr as its own kind of thing, and it does come up with fun threads in its own way.