There's being "pro-copyright" and then there's just the topic of paying artists, and then choosing not to pay them.
Which sometimes is bizarrely and belligerently defended like some moral stance (barely even in relation to copyright/piracy), and sometimes bubbles up like tools that not just avoid paying artists, but make it harder to pay artists, even when those artists have something set up that's a far cry from ad driven platforms. Like, it's not just 'removing third party ads', it's removing any surface and any mention that may have artist selling their music. Is that even about copyright? The music is available to listen either way so it's hardly even infringing that way, it's just that something like this app chooses an active stance (how else would one describe actively removing everything about paying aspect) that's against paying artists, at all and in any form.
It's not even about 'what does downloading music entail', it's just 'fuck paying artists'. Music has been beaten towards kind of just giving up and making things free to stream and just kind of hoping to get their money elsewhere (concerts, merch, music sales), and yet still some people want artists to shrink with their "paying for art bullshit" even further as to preferably have artists not even mentioning that and themselves not seeing any of that at all.
It's not about choosing which artists you like and whether you want to give money to some particular artist or not, and not even just personally refusing to give money to any artist.
It's about going out of your way to create something that gets in the way of artists getting paid, such as obscuring/eliminating an option to buy music or give money to an artist, not just from yourself alone but from other people, who might not even have such a stance, or even realize that there has been an anti-artist decision made for them.
Not even adblockers go this far, because they just remove third party ads, and artists are still free to promote their stuff in other ways (for example, on youtube, there's still stuff in description, annotations, things inside the video, etc.). A player like this removes those options from artists completely.
It's also like, not even that different on bandcamp - you can just listen to some music there and move on without buying it. Removing an option to buy an album is kind of different. Imagine if ad blocker did that to a bandcamp webpage, that would be absurd. (bandcamp doesn't even have ads though. well, depending on what you consider "advertising or promotion", maybe the whole website looks like endless promo to you, if that's the way someone looks at entertainment)
It's there when you listen on bandcamp, it's not there in the player. It's removed from the listening experience in this app, and made further obscure by not linking out. Are we actually gonna argue whether a "music player focused on streaming" that touts removing everything else, isn't doing the thing it's doing?