Because I like wavy, voluminous hair, THAT'S why.
The first panel is absolutely true. I thought of several setups for bringing up this topic, and none of them worked particularly well given the space I had to do it in.
In any case, this comic is inspired by the fact that I'm tired of hearing this argument, and I'm particularly tired of hearing it in YouTube videos in which the thing being spoiled has nothing to do with the subject of the video.
It is an argument that only holds water if someone should have reasonably expected spoilers in the first place, and spoiling something by way of non-sequitor is just a dick move. What's more, the people doing it KNOW it's a dick move, because they immediately whip out the "it's x years old" argument in spite of being pre-recorded and reacting to no one.
"Everyone's seen it by now" shows a very narrow perspective regarding other people's personal experiences, and the argument is extra flawed in cases when spoiling movies that much of the target audience was too young to have seen when they came out. In a lot of cases, they wouldn't even have been born yet.
The argument does, of course, hold water if the spoilers should be expected. If you click on a video saying "the top 10 most shocking moments from The Last Airbender" and you're on season one, complaining that they spoiled the ending of the series is just irrational. Watching that same video and having major spoilers dropped about Teen Titans, however, is a different matter altogehter.
Sidenote: Real Genius's ending was actually spoiled for me by Mythbusters. I didn't actually mind that, but it's worth noting, and I almost tried to think up a different example because of that, as though I was somehow going against my own canon by making this comic.
Sidenote sidenote: This got sorta ranty. I hope I remained at least somewhat coherent ^^;