When applied to a genre of music, the term "soul" is pretty specific. I would only use the term in describing music if I was talking about the above-mentioned "Kings and Queens of Soul" (Aretha Franklin, Al Green, etc.) and avoid using it in reference to someone's musical talent.

In talking about guitar playing, I tend to avoid terms such as "soul" because I think it causes ambiguity and even confusion. I might say that a particular guitarist puts "heart and soul" into his/her playing (though I probably wouldn't), but I would never just say "this guy's playing has soul" because to me it seems inexact and much too subjective, and in fact it might possibly be insulting to some.

As for what the journalists are doing--jeez, who cares? If music writers could play music decently, would they be sitting there trying to think of words to describe music? I would rather listen to my least favorite band on a transistor radio with a blown speaker than read what some journalist thinks about my favorite band.