People like Owaisi always spread hatred comments and still get away. Whereas any other religion political leader that would say the same would get thrashed by the media.
He and his henchmen are quite famous and popular for hate-speeches.
So, the answer is, because of the widespread communal attitude among general Indian citizens, and predisposition towards seeing one side of the coin (as same as this question).
it stems from the lack of Liberalism.
which stems from the lack or low-quality of education coupled with racism (casteism), and religious bigotry.
Indians have a tendency to be collectivist, and that makes it really easy for politicians to 'target' specific groups of people, it's all just pure pandering. They realize the ease with which you can gain power if you leverage these unified voting blocs. In this case, Owaisi sees it more beneficial for him to appease the Muslims - even if it means spewing hateful, nasty rhetoric against other groups of people, since his constituency has a clear Muslim majority.
By the way, not all media present the same narratives, there are news outlets which condemn Owaisi too, it all depends on who owns these media outlets (and their connections). If you see a news channel unreasonably criticising some personality, take a look at who owns the media, what are their motivations, what are their financial interests, who is financing them etc. Just follow the money.