The problem with Brazilian teams is that the country's coaches have outdated philosophies and are tactically much inferior to European coaches. Just watch the Brazilian national team's games and you will see that the team does not even have a tactical scheme. There are many deficiencies, especially in positioning, which have been happening for years.
Then what prevents the Association from hiring a good foreign coach? BTW, Brazilian coaches are very successful across the globe. The rot is much deeper and in many cases coaches are just convenient scapegoats. The quality of Brazilian football has gone down, both in terms of international matches and club matches. Most of the players are migrating to Europe and the middle-east, as the local leagues doesn't have required strength. In the end, this contributes to the never ending decline in terms of quality.
CBF all system need overhauling which can bring good changes with currently their many sponsors also have good influence on teams selection which is bringing their quality badly down if they are able to end few things and have good merit policy then things can take good changes in near future.
Sometime back there was talk about hiring any foreign coach but this end without any strong argument due to no interest from few top tier coaches from Europe now things are still hanging and no one able to force improvement even they are still full of quality and skilled players. Brazilian League is also losing it's charisma as things are not working on merit and their economy is also having problems which are not giving support which can bring good changes in structure development.