I think a lot of fans were quite heavily sold on the "blue wall" and the "designed for atmosphere" claims given by the club and Meis over a very long period..... from the initial consultation phases to the big design unveiling, and then through the whole construction phase, this is what was repeatedly sold to us etc.... There's now some disappointment that somehow it isn't quite the "automatic" cauldron that many expected. Yes, it is people who make the noise, but the design can greatly influence how it all works and even help prompt that process.
There can also be a big difference between designing a "whole stadium" for overall good acoustics, and designing a "home end" for atmosphere. For it to be the engine room (a la the yellow wall) for really generating and boosting those chants, filling the home-end with noise, which then fully engages the whole stadium to give a great atmosphere. Unfortunately, the high roof of the South stand, its slightly upturned geometry and the large gap between back row and roof, means the "acoustic catchment and feeback" for that end isn't particularly great. At 63 rows it also isn't that big (just a few rows more than the Gwladys St in fact). On top of that, the demographics of placing the most vociferous fans in just the bottom 27 rows (most distant from the roof) means that it's probably not the real "muscle" stand that most expected. Compare that to how Birmingham City's architect describes the design of their proposed stadium, where he mentions the "squeezing of that space" between roof and fans to really amplify the sound. We went for an elevated barrel roof, great for containing whole stadium noise generally, but slightly vacuous for generating home-end noise advantage.
Yes, Goodison also wasn't great for atmosphere for many games, and it certainly wasn't designed for its acoustics in any way, with its relatively tall stands and high roof lines etc.... However, in the days of standing and particularly for 50k+ gates, it was always extremely noisy. It never had a kop-type terrace, but the tight overlapping stands brought everyone much tighter to the pitch and that, plus standing and sitting on all sides meant that it was very responsive to any incident on the pitch, so that when the blue touch paper was lit.... the quietish arena became an absolute bearpit. Before the 70s much of the noise came from the sides with the large Goodison Rd terrace producing the bulk of that famous Goodison roar across the shorter (cross pitch) axis.
The new stadium is an even more cavernous space to fill with noise, but when that high threshold of engaged fans is met, then the barrel roof will ensure a great "whole stadium" atmosphere. Simon Inglis, the well known writer on the history of football stadiums wrote that Goodison was famous for the atmosphere that prevailed there on special occasions.... I think that might also be the case for our new stadium.
Of course, there is also that whole "bedding in" process where the most vociferous fans eventually find their place and the atmosphere can really evolve. For instance, when the Green Brigade relocated to the corner section at Celtic Park, it marked a real step-change in the atmosphere there. Perhaps if an upper corner section (or both) could be better utilised in this way, then those really trying to affect the atmosphere, would also find greater acoustic leverage just under to roof, to keep the atmosphere at least simmering, for all games! Time will tell. To this effect the North stand is a bit of a damp squib.... Goodison at least felt like it had 2 home ends.... far less so at BMD. Maybe this will develop too.