It really, truly just boils down to that. You're not going to switch to Netflix. Or Hulu. Or Apple. Or buy BluRays. Or watch it on YouTube. You can't - they have monopoly. Every dollar they put into the quality of the app is eating into the margin. There's no pressure to increase quality. It needs to just (barely) work so you suffer it enough to watch.
The software engineer can throw out the laziest, fastest turd, the UX designer can do the bare minimum and the product manager can sleep on his job and money will keep coming in.