Earlier quoted context omitted.
Wouldn't say people are happy. "They accept" is much closer. They accept the mediocre, because there's nothing they can do about it, and they don't understand how any of it works.
I’m happy. It’s not really a big deal to me if my uploaded content is removed and I think the service that Spotify provides is worth more than what I pay for it.
That said, I'm no longer using Spotify, and disappearing songs had a lot to do with it. I've been paying for a premium account for some 6-7 years, way longer than I should - it took me over a year to notice that I'm not actually using it, because half of my favorite songs are gone, and whenever I search for something particular, half of the time it's not there (or worse, there's some shitty cover of it). And it's not just the catalog that suffered since - also the UI of their mobile app rotten over time, and became incomprehensive.
But back in ~2012 - 2015 I sure as hell was happy with their service, and evangelized it to all my friends, and I did feel it's worth more than what I'm paying for it.
I guess losing music on Spotify isn't that big of a deal for most people, because - extrapolating music-related behavior from a couple dozen non-tech people I've observed over the years - the most popular music player isn't Spotify, it's YouTube. And YouTube does have it all, at least for now.