Also, they didn't say it's bad because it's from reddit, the statement could be interpreted as saying that it's bad, and also that it's from reddit. Imagine http://laurencetennant.com/bonds/adhominem.html applied to the genetic fallacy, and you'll see what I mean.
If you want a simple explanation, just say so. There's really no need to use internet memes for basic communication.
The only English words I could find matching that pattern are elicited, elicitor, elidible, eligible, eligibly, elisions, elitisms and elitists - none of which seem apt, although "elicited" is tantalisingly close. From context I always read it as "elucidate" (elu6?)
So why isn't it Elif?
Probably not the real reason...
(In truth, the "like I'm 5" part is not obvious so could be misunderstood, but is easier to grasp the meaning.)
I thought the guy meant: "I don't like it because it's from reddit."
But ikeboy has it right: in this case, because reddit is not a person, it's a genetic fallacy, not an ad hominem. Which I didn't even know existed. And, of course, he didn't say that it was because of reddit, so it wasn't even that :)
Redditit is childish, racist, sexist, ignorant and a hive mind.
eli5 like most things on reddit includes this. There are a lot of under currents in the term.
It shouts it's ok to be 'proud' of being ignorant on a topic.
Rather than the adult, it's ok not to know, just ask someone for a simple explanation. Adults should know you don't need a meme to hide behind to say I'm not good at this.
I'd be very surprised if the majority of people on HN don't also Reddit for our fix of what humans are at their base level but the point is HN is supposed to be better than all that.
Some people on Reddit may be that way, but that doesn't mean everyone is. Some people everywhere are that way, still doesn't mean everyone is. Try not to be so hateful.