This may or may not have to do with the discussion, but I think i may have come to a conclusion for another reason people dislike modern SST... the street itself... it's so "busy" anymore.
I mean, let's look at this historically: in the old days, what did the street consist of? Two main structures (123, and the tenement building), and a secondary structure (the carriage house). That's it... yes, there were locations: Gordon and Susan's apartment, Hooper's Store, the Fix-it-Shop, Oscar's can, Big Bird's nest, Ernie and Bert's place, etc, but the street had a small number of these locales and a small number of structures where you could basically easily find where everything was at, aside from those three structures, everything else was basically painted backdrops.
Now, there's NUMEROUS secondary structures and locations have made up the street: Elmo's apartment, a community garden with additional back-window apartments surrounding it, the subway, the aging abandoned Furry Arms and Finder's Keepers cobbled together nto a dead-end alley around Big Bird's nest, a flower shop, etc... it's hard to keep up with all of this locations and such for people who were only accustomed to being familiar with Fix-it-Shop, Hooper's, and 123.