How else do you promote music?

Play them on the radio.

What station do you work for? I don't really understand how the radio thing works. I don't believe that DJ's are a fan of half the mainstream music they play. I don't understand why they refuse to play certain types of music at least once a day. Like, dedicating maybe 30 minutes to Indie Hip-Hop/R&B, etc. Who enjoys hearing the same 10 songs every hour of the day?

If critics really want to [attempt to] positively influence a musician's career, then I think they'll have to do more than just write reviews.

not really the objective of any critic i hope

Well, by giving a record a positive review you're saying to people "hear this/buy this". What's the difference?

Did I misunderstand you?

I volunteer at KOPN 89.5fm where I host a show every other Wednesday night and sub at other times when asked. I used to have a weekly program on Thursday afternoons. This is the page with all of the archived playlists for KOPN programs. I hosted Holy Victrola (thursday 3-5pm) until the end of July of this year and now I host Thick Cuts.
I can play whatever I want and I try to play music that people don't normally get to hear on the radio. I play as much new stuff as I can. I spend a lot of money on records. I also support my programming with the collection at the public library in my community, which has a surprisingly large and varied collection. I'm not sure how it works in commercial radio, I've never gotten paid for my programming and I suspect I wouldn't be interested in that kind of radio.

It looks like all my Holy Victrola playlists have been taken down.
I have a feeling that someone at KOPN isn't that excited about my programming.