This does however suggest something. The problem here seems similar to the problem of piracy in general, in that people choose content delivery format that sucks the least, and then delivery platform that they understand.
Consider the case of movie piracy (and for simplification let's exclude people pirating because they don't have money): people often torrent movies because they want to get a decent-quality mp4 file instead of a half-assed player and a third of an operating system that together deliver half an hour of unskippable ads and piracy warnings. Consider the case of videogames - when Steam showed up, piracy went from something everyone does to something shameful among gamers.
Or just today at work we're talking about a streaming site that serves soccer league games. One of my cow-orkers pointed out that this is about the only reasonable way to watch soccer games, because otherwise you'd have to buy subscription to half a dozen cable services - as different leagues have deals with different companies.
Now imgur is a no-bullshit source of images. People know and understand it. It's no surprise people prefer it, and for non-imgur sources you can often find requests to reupload the image to that site.
As for solutions - I don't have one. I don't believe reuploads themselves are a problem. Lack of culture that would encourage attribution is though. But the expectation that you can make money by posting content on the Internet is a bigger problem, IMO. Smart content creators know their work will be copied, reuploaded, shared without attribution, etc. and so they don't base their livelihood on posting stuff on the Internet. Those less smart end up complaining about unfairness, but that IMO makes as much sense as complaining that gravity is unfair. Digital works are inherently copyable, it is in their nature.
To be fair, this is actually a problem with the environment that goes way beyond the individual pieces of content, and is one of the reasons that Alan Kay thought that the Internet was professional but the Web was amateurish.
Alan Kay's idea was (paraphrasing) "It's great that we have message passing between client and server processes, but we really needed to take this idea and run with it, with each piece of content on the Web being some sort of network-hosted process which you communicated with. Then you by-default preserve provenance (who the author is and how it got here) and then you can integrate micropayments into browsers so that you can earn money for watching ads (and target the ads that you want to watch!) and then use that money to browse the content that you want to watch, etc., with by-default the content-creator reaping the micropayments of their content."
But because nobody solved this rather difficult problem, we have freebooting and you have to reload web pages whenever you change their source and re-navigate down to the menu that you care about, and Brendan Eich is now getting flak from people for trying to reinvent advertising on the internet etc...
