I agree that there is no need to overestimate Brazil, but you can't judge a team for their performance in one playoffs. Playoff games are always risky and it's pretty easy to lose a game even if you are playing better than your opponent. I'm not saying that Brazil was better than Croatia when they lost, but I agree with Docnaster that Brazil would have won at least 7 out of 10 games against Croatia. I guess that in Qatar it was one of the three games where Croatia wins.
Their playoff performance was also below expectation. They started well, with a 2-0 win against Serbia (probably the second strongest team in Group G after Brazil). Then they had to work really hard for a win against Switzerland, and managed to get full 3 points only due to a goal from Casemiro at 83rd minute. And then came the shocker, when they lost 0-1 to Cameroon (Vincent Aboubakar scored the goal against Brazil in 92nd minute). Their only big win came against South Korea in the round of 16, when they won by 4-1. Overall, it was a disappointing performance from Brazil.