That's the point, the "rock" stars aren't making any money in the industry like other pop acts anymore - they're mostly doing their own thing on Patreon and streaming on Twitch.
If they're recording music, they can certainly still use Logic to do it, and Apple wants to give them reasons to keep doing so. It's hard not to notice that Apple has been courting YouTubers really heavily over the last few years.
Like many other things involved in this decision, it's the perception that matters, not facts.