Lots of people think it's essentially a dead end as it's missing some kind of 'secret sauce' that the brain has and which we are just too dumb to figure out.
It's a lack of appreciation for how complicated the brain really is. The "secret sauce" is "it's really frickin' complex and we don't understand a fraction of it". It's like comparing an abacus to the latest AMD or Intel CPU and saying, "The abacus is a dead end because it's obviously missing that "secret sauce" that this magical computing oracle is doing"