I see that issue very differently. The way I see it, reposts are the best way to honor a meme. If a meme doesn't get reposted, it just gets buried in someone's profile and people aren't as likely to see it after it its initial run. My greatest hope for my memes (or comments), is that someone would see that they're funny enough for others to enjoy and repost them in a good context.
However, since imgflip's guidelines say "No obvious reposts," I usually downvote reposts of memes that are currently on the front page.
Those are some of my thoughts on it, for what they're worth. :)