Swen isn't a game journalist, and I also think that Steam reviews are different because of what I said before.
Steam reviews are just a thumbs up or thumbs down, and people use that to communicate if there is something wrong with the game.
If a game has a mixed score that's a lot more of a warning than if a game gets a 7 or a 6 from IGN because usually that means that there's significant technical issues.
I don't care about reviews but if I see that a game has a mixed or heck even mostly positive score then that makes me second guess and I'll look into it further before buying.
Monster Hunter World is a good example of this, back when I bought it on Steam it had a mixed score because of connectivity issues.
So it made me second guess and research the game more but ultimately I did buy it, but I didn't buy it right away because of that and with other games I've put off buying something because of it.
I also think that people in general trust users more than media outlets, users aren't perfect and there's a lot of dumb reviewings but generally speaking they tend to get cancelled out.
Edit: Also Steam reviews are in your face in the store.
An IGN review is something you have to either seek out yourself or stumble upon on Youtube.