>>1626309The association comes from /pol/'s 'meme wars', which would make pepe the prime meme for the reddit and phoneposting influx /pol/ and the rest of 4chan got towards the end of last year.
Essentially, it's no longer a 4chan meme. To the rest of 4chan, it means nothing.
The proper definition of meme is an idea or thought present in a certain group of people. The meme can be used as a method of recognition between group members, if they know the memes you do they're part of your group.
Therefore, a meme is only good as long as it's kept within its group. Pepe's not a 4chan meme anymore, so 4chan dislikes it, just like it dislikes other old memes.