Most of the memes come from communities where the typical user is way too comfortable with things like photoshop, so they can crank out a gag before it suddenly seems like a waste of time. Even the "slapped together" looking stuff takes longer than you think. This skill set - funny but also has casual graphic design skills - is narrow enough that even their throwaway jokes tend to get passed around and around and around for years.

This community is more, uh, engineering focused, so they're doing pretty good to find reasonably funny people to screenshot. For what it's worth, I agree with you, but the internet always has some tiresome gotcha post to shut you down with, lest you set any boundaries for yourself, so everyone's stuck with whatever people feel like calling a meme.