Well Gabigol has been the bright spot for them.
But while like I said Neymar's performances haven't been great or up to par like one would expect it doesn't help the team is tactically bad and some of those players playing there are no where near good enough to be called up.
In my opinion Neymar put himself in a very bad position, he chose to play in a tournament that's being held in his own home country, and after the 7-0 the expectations were high for Brazil to obtain the gold. I mean Brazil is the only national team that brought in a true superstar if I'm correct, they were gunning for the gold, if they fail I wouldn't want to be Neymar at all.
Tactically wise the team might be bad, but again they aren't playing against powerhouses, maybe the young Brazilian players aren't that good aside from a few like you said.