If the time-horizon is the next listen, it's terrible, as it doesn't care if it revolts the user so badly that they leave the platform immediately. This is bad for the platform, too, so they won't do it for long.
If it's very long term, then it's not as bad because it takes into account users listening more often and over a longer period of time. One way of getting additional longer term listens is including signals like tastes of similar users and other things many of us music-lovers would consider "good". And the profit part means including signals like cost-per-stream of each song. A very long time-horizon requires finding good tradeoffs between all these signals.
My guess is the time-horizon is monthly to quarterly. This is because of market pressures (public markets demand quarterly results) and the practicality of measuring the results. You can't measure/improve infinite time-horizon optimization.
This will still have the effect of selecting for users that aren't as sensitive to what they are hearing. They will not leave as quickly. These are the users the platform wants, as these users afford the platform more leeway in shifting the tradeoff from quality signals to cost-per-stream. Eventually, this will push out many of us music-lovers and the artists we love. Once this reaches a tipping point, there will be room in the market for another service to cater to music-lovers. But, given market pressures, they will almost certainly walk the same path as Spotify in the long term.
For me, the implication is to own my own music. I always have and always will. I only use streaming platforms for discovery. But as soon as I decide I like something enough, I buy it. I almost always buy albums, not individual songs. That lets me see if I want to follow that artist more deeply. This is expensive and time-consuming relative to streaming. It's dirt cheap relative to what I get out of music.