When I started trying Apple music, I though the same thing. Music discovery an recommendations were dreadful. I don't remember where I read it, but searching for ways to tweak or help set recommendations, I read a post, which I'll paraphrase because the gist of it is all that matters.
Basically, if you've been using Spotify for well over a decade, it has well over a decade of listening history, thumbs up/down, skipped tracks and so forth to pick from. Using Apple music (or any new service) for an hour only has an hour of history. They're not the same. Give the new service a month or so of exclusive intensive listening, take the time to choose specific albums and genres and be sure click the like/dislike buttons. Then after a month or so, let it roll on random and see what happens. You still might not like it, but at least the algorithm had a fighting chance to get you know your tastes.
It's been 2 months now, and in my opinion, I'm getting better recommendations than earlier, and it's completely stopped playing the artists I constantly thumbs down.
It's also my opinion, at least for me, that Spotify's generic "my radio" is much more varied. On the other hand, Apples "song based radio" is more consistently like the original song, even 3 hours later.