It's more the point that screencaps used to be about the dumb thing that was said, not the 50 people begging to be in it.
The point of making the screencap was, as you said, to record something funny/creative/memorable that happened. It usually just consisted of a series of relevant posts, and perhaps a full-size addition of any related image. Some reactions may be thrown in if they were amusing or added something, though often times just seeing the sheer number of responses linked in the post was enough. Now it'll be some relevant posts, followed by every single person that responded to it having their posts poorly resized, snippets of text copy/pasted all over, and several "ADD ME TO THE SCREENCAP!" posts just because. It's the text equivalent of photobombing something with wide eyes and your mouth hanging open like you're faking surprise and excitement as so many douches do. The reactions take up more space, draw more attention, and overtake the original post in terms of relevance in it's own screencap.
The thing that gets me is the sheer lack of creativity that goes into what qualifies as a screencap anymore. There would be effort in them, or it was just the fluke result of some random collaboration between anons. Now it's “Ha, tha’s fookin’ wild, innit?” over something as trivial as a 12 year old not knowing how to put his hands on things. And why wouldn't it be? I don't really recall the last time I saw someone put effort into making something noteworthy for /co/. Hell, /a/ had that Seinfeld x InuYasha crossover fic that someone wrote, and people were blown away by the fact that there was OC on their board. Now THAT was worthy of a screencap, and look at it: only the story. No reactions needed. There was a second cap someone did that showed the number of linked posts, but that was it. How are we letting /a/ be better than us?
tl;dr - I'm a bitter old man, and things were better in my day.