I am a bit baffled why you guys are surprised.
Youtube is literally broadcasting content, it has it in its title ("Broadcast yourself") and thus you need a license. A proper media license where you gotta note how big your audience will be. (I licensed music from Audionetwork and they wanted to know the possible range, e.g. 5000 or more and rate accordingly). On a highly visible platform, if not THE video platform of the planet. The risk is literally 99% each time you upload something there. Either the copyright holders do not care or we deprive the artists of their royalties by doing that.
Sharing it on forums like this is a completely different thing as we do not broadcast anything. We do not play back the music here, there is no player on the website. We do not use it in any production (e.g. video clips, cooking videos, instructional material,...) We are literally several layers underneath a Youtube video playback. Sharing is of course prohibited as written on the LPs and CDs themselves but as said, it's far off from just uploading a Youtube clip and, well, broadcast production music in a production (even if it is just the cover art) it to a worldwide audience.
Also, I mentioned it before: By removing https or anything else you disguise absolutely nothing. Just like your search engine, those gaps are filled in. Do you think copyright law firms are not finding us by using "pixeldr@in" or something else? The hotlink helps only for everything under the very thin threshold of law enforcement.