Its apparent that radio was removed in favor of this "Created by spotify" playlist radio which removes the ability to get the personalization of thumbs up and thumbs down. This clearly is undesirable for any user and is a bug, not a feature. Many are requesting the personalized radio stations with thumbs up thumbs down buttons, but these posts are buried by spotify. It turns out spotify still supports the old school personalized radios, they're just hidden, which introduces many bugs into this poorly designed service. Here are a few examples of why this is a bug, and why spotify developers better hurry up and unf**k radio before they lose more customers.
If you click "Go to Song/Artist/Playlist" radio for song/artist/playlist X, you get sent to a playlist titled "X Radio" which is really a radio playlist "Created by Spotify", with no personalization (thumbs up and down) available. But if you open an old school radio station on desktop by going to your stations, you get a "Song/Album/Artist Radio based on X", and on desktop the thumbs come back! So there are two notions of a radio, the old school personalized radios, and the new school bs absolutely terrible created by spotify radios. This creates the following glitches and inconsitencies:
The list goes on and on of how confusing, backwards, and pitifully designed this radio feature is. The old one was great, and you ruined it and lost a ton of customers in the process. Here's a link to the 100000000 posts of people requesting you to fix this, which got ignored because your community is a disjoint mess (people make the same posts independently and you ignore their requests because each individual post didn't get enough attention).
...the list goes on but I'm getting bored of this. But better include this fun fact for anyone else who misses their old school personalized radios: open desktop, find the song/album/artists you want a radio for, and click and drag that to "Radio" button in the top left of the screen. You will magically open into the old radio with thumbs up and down. Don't think you can save it though, thanks spotify.
P.S. No customer should have to waste their time fixing your problems, I contacted support but they couldn't put me in touch with your hopeless dev team. For you own good you better fix this but while you're at it either hire me or give me free spotify for life. Music is so important to people and it really sucks to see you guys mess it up so bad.
Updated on 2019-09-04
Hello and thanks for bringing your feedback to the Idea Exchange.
A similar idea has also been suggested here: https://community.spotify.com/t5/Live-Ideas/Mobile-Bring-back-Thumbs-up-down-in-radio/idi-p/4669906
We have also merged the votes from this idea to that original one. More information about how the Spotify Idea Exchange works can be found: here