The whims of youth/geek/nerd culture is probably primarily responsible for the explosion. However, one thing that has probably helped with meme adoption among academics is the fact that memes found on the internet are more like the genes of molecular biology. One of the historical criticisms of memes is that they are not digital and discrete - and so are not much like the genes of molecular biology. Of course, the term "gene" has historically had a quite different meaning in evolutionary theory - but not everyone understands that.
Anyway, memes on the internet are digital and discrete - at least for some of their lifecycle. The ease of classifying the resulting discrete variants makes it more obvious that gene-like dynamics apply to their evolution.
Daniel Dennett described the internet as the drosophila of memetics in 2009. The internet is the main object of study for memetics - but it's also the crucible in which many memes form. Not just the the "drosophila of memetics", but also its "warm little pond".
Many evolutionary processes tend to start off with low fidelity. After a while, they become advanced enough to invent digital copying, there's a digital revolution, and things mostly stay digital from then on. We've seen a digital revolution going on over the last few decades. It seems likely that memes will retain their more gene-like dynamics far into the future - effectively eradicating one of the sources of confusion about memetics in the process.