I don't really see the need to be so combative. I've been fairly respectful and honest in my replies.
your argument only makes (the tiniest amount of) sense if everyone in the world was only interested in movies, tv shows and books in the most superficial way possible, only caring about the handful of big budget, over-hyped and over-marketed releases every year. or, taking it one step further, did movies and books not exist before you were born? or are those all fair game? or, wait, let me quote you again here:
right, so, if there were a century worth of cinema to be interested in and movies did exist before you were born, you'd "have found the time" to watch - let's be conservative here - 1000 movies before, what, the age of 3? or let's be reasonable and extend it to the age of 18? and then let's throw books into the mix... thousands of years of writing: fair game! or alternatively: if you "cared" enough you'd have read all of them before anyone had "the chance to spoil them for you"! LOL!
Anyway, to answer your points, and obviously I can only speak for myself: yeah, I basically agree with the joking way you have extrapolated my logic. However, your argument rests on the idea that I'm interested in all things ever. I am not. I have a range of things I keep a general interest in, specific kinds of Science-Fiction let's say. I honestly doubt there is much out there that I actively know about, am considering consuming, am genuinely interested in, and is many years old, yet I haven't somehow found the time to watch/read. I'm being sincere here. You're not going to catch me in a situation where I'll go, "but, but, I was going to watch that 20 year old movie at some time in the future maybe - how dare you talk casually about it!"
I waste too much of my time to actually hold a "all things are spoilers" position. Every Sunday I choose to watch a terrible episode of the Simpsons instead of catching up on Silent Running, a movie you can spoil for me if you'd like. I've been meaning to see it, but honestly, I am probably never going to get around to it. I've had countless opportunities to watch it now and have consistently chosen not to.