It is obvious every captain should support their players expecially before such mega event. Like we common citizens and media, a captain cannot criticise his player right away. If he also critises him, then it will lead to weaken his confidence further. So what every captain has to do that only Dravid did on Sehwag.
For ex. if u get poor marks in school, everyone critices u, but not your parents. They should support you and give more confidence, so that u perform well. A captain also like that.
We all know what is the potential of Sehwag. Such bad patch in the career has happened all so called big players such as Sachin, Dravid and Sourav. They survived and still surviving because their captains have supported them in their bad patches. This is true not only in cricket, but in real life.
As an indian citizen, at this point, we should wish the team all success and should not criticise. It is not the right time to critcise.