People with a Leo sun conjunct Pluto (boomers) can be extremely powerful-- or at least perceived as powerful by others. But consider a younger person with a Pluto in Scorpio square sun. They're liable to have a lot more insecurities because a hard aspect to the sun typically plays havoc with one's identity.
Hmmm... maybe these "modern astrologers" the OP references are solar Leos from the Pluto in Scorpio generation (or, I suppose, any sign from the Pluto in Scorpio generation). For that matter, maybe the OP him/herself is.