19 ( +1 | -1 ) too slowi think they (whoever) say that the Bc4 Bb3 sequence takes time, so leaving the bishop on f1, you have a faster kingside pawn rush by two moves. but i am no expert to know this for sure.
19 ( +1 | -1 ) "They" are maybe Nunn and Callagher in the book about the Najdorf? 1998,Batsford, chapter 1. (I don't think 6.Bc4 is a bad move for an average player like me against an average player like me....)
144 ( +1 | -1 ) vertho ...I still play the Fischer-Sozin line with WT and feel like there is a lot of room left for improvement and innovation. I think you hit the nail on the head when you suggested the current state of affairs is "fashion", imo. But that could be wrong. Its more of a feeling than something Ive researched ... & knowing that fashion is a most common motive when preferences shift. Or sometimes just a high-profile game where someone does well, rather than any outright refutation being found. What made Be3 so popular?! Quite likely the fact that it was considered rather lame and unenterprising during the sozin heyday. [As far as a key game that was particularly wonderful for Be3 or devastating to Bc4 ... I cant point you to one. Maybe someone else knows of such.] Anyway ... since Be3, and especially linked to f3, was considered so poor previously, it may have a lot of previously uncovered territory to play thru now. Undoubtably someone did use the line effectively in GM play and started a trend towards it. Perhaps those noted for playing "The English Attack". I wouldnt hesitate to venture the Sozin if I needed a win vs the Sicilian. But have also liked playing Be4 and Be2 vs Scheveningen lines. Still do not care for it as much vs Najdorf lines. Bc4 always seems much more fun and still has lines that have never yet gotten GM tested. So seems very fertile ground for making a mark upon opening theory.