I just don't get the consistency of the list. Is it supposed to be complete aesthetics without regard to mass? In which case as I said, there are definitely pros on the list who should be on it who would be smaller than Steve Reeves.
I think it's just a list of physiques Shawn admired the most for a number of reasons. I don't think you could defend the list using any particular standard. A top 20 mass monster list would be easier (just list the 20 biggest and most shredded pros of all time).
Lots of pros would look as "aesthetic" as Steve Reeves if they just lost 50 pounds of muscle! I'm sure there are some skinnies on this board who could bulk up and look just as "aesthetic" (small) as Frank Zane. Sure, he has a great physique that I would much rather have than any pro out there today - BECAUSE HE ISN'T A MASS FREAK. But I'm not going to say it's because he's "aesthetic". It's because he looks like he's starving compared to pros today who don't look good when it comes to the reasons why I work out (e.g., being healthy, being balanced, and attracting chicks). I remember a dude in a class of mine did a project on the evolution of the look of a bodybuilder and interviewed girls on campus and they all said Zane looked the best when compared to pros from the early days up to Ronnie Coleman. The dude who made the project was a clear juicer and went on about the negative side effects of juice. 
I'm sure if pros today trained to actually look attractive to the opposite sex and not build physiques that scream of narcissism and obsession they would also look "aesthetic" (e.g., be 50-100 pounds lighter).
Matt the list is composed without reguard for mass? Cormier competes at 250lbs , Haney 250lbs , Paris 230lbs , Reeves 215lbs , Samir 183lbs at his Olympia win and into the mid eighties he competed at 205lbs , Labrada 175lbs , Makkawy 160lbs , Zane 180lbs , Medenhall was 230lbs , Clairmonte I believe was 230+ lbs , Sergio 240lbs , that list covers all sizes , heights are weights , to say the list is picked without reguard for size isn't accurate , its just there haven't been many examples of truely aesthetic bodybuilders 250lbs + .