Because the number of people who can tell the difference between 480p and 1080p is much greater than the number that can tell the difference between 128kbps mp3 and 24/96 FLAC.
EVERYONE can tell 128kbp vs FLAC if they listen even a bit. 128kbps was always bad, especially if it's an old upload.
320kbps (which is ~Spotify 'extreme') vs FLAC is a different story, you do need some reasonable (read at least a $30 soundmagic E10 in-ear, not some wunderbar looking designer latest fashion trend on-ear for $200+) equipment and some training to spot that.
EDIT Also doesn't tackle the problem that most people hear music, not see it, so 480p vs 1080p for MUSIC isn't a deal breaker now, is it?
I've always wondered if 320 is supposed to be distinguishable from lossless.
Like, wasn't MP3 encoded at 320kbps designed to sound like a CD, while still being compressed? If it's still possible to tell 320 from FLAC in enough circumstances, then is that a failing of 320? If so, why stop at 320? Why wouldn't there be a bitrate somewhere between 320 and uncompressed that makes it impossible for practical purposes to tell the difference between lossy and lossless?
Does a 1% compression jpeg _supposed_ to be distinguishable from the orginal? Probably not, until it goes into a 4m x 3m print.
MP3 does the same to sound that jpg does to colour: those similar enough become one. And it also cuts off the "inaudible" sounds. If you open a spectogram, 320 still cuts at 20khz, whereas most CDs have until 21-22khz - because there are people out there who hear those sounds. (There are some "ultrasonic" cat & mammal scare away devices, which I hear, and they are literally painful to me.)
But answering your question: no, the goal was to have a good enough, but massively smaller file. The goal was never not to be possible to tell them apart.
FLAC compresses a CD to roughly half of it's size - that's already a big win.
Perhaps he should have rephrased it as number of people having 4K screens and full HD on all devices they use is far higher than number of people have good audio devices