I'm guessing you don't have much knowledge of modern Hindu history? To be fair though the media doesnt really report much in the way of attacks on Muslims by other religions or ethnic groups, so Hindu nationalism / saffron terror falls off the radar. Its very important to the western media that incidents are not categorised as an act of terrorism unless that act has a perpetrator which is Muslim, whether the injured are Muslim or not is irrelevant.
Granted I'm not disagreeing that Sikhs and Hindus are not carrying out similar attacks like you said but the western world isnt throwing bombs, flying unmanned armed aircraft aimed at destroying Hindu populations, nor are they attacking India, the UK, Canada or the USA which is where the majority of the worlds Sikhs live.
I mean, the western world doesnt care about dropping bombs the Middle East and Asia... its been doing so for a hell of a long time,
why arn't we all called Christian radicals. I guess we are just better at bigotry