Google Music was decent. This new replacement is not so good. The "I'm Feeling Lucky" mix was generally right. The YT versions are good for about five songs and then trail off into Do Not Like. No amount of thumbs down seems to be making a positive change.
I'm surprised thumbing things down isn't helping you - it was the thing that fixed YTM for me. I wasn't thumbing things down enough, now anything I don't want to hear again I thumb down, and I mostly listen to the personalized and discovery mixes. You might need to switch/reload stations for it to take effect. And IIRC the discovery mix only updates on Wed.
One thing that I seem to remember it having was a social aspect. Twitter doesn't treat its lists very well but it is possible to find somebody that you want to follow, then see what lists they're on. Maybe that leads you to other people that you want to follow.
The thing about blogs is that typically the signal/noise ratio is higher than Twitter accounts.