First of all, there is widespread criticism from many sides including from the Hindu sadhus and there cannot be any justification for any violence related to eating beef or anything else in India or any other part of the world.
What sometimes is not mentioned in this debate is that the first major voices against animal killing did not come from Hindus but came from Buddhists and Jains who influenced Ashoka and Akbar (and Jehangir) respectively to install new laws against animal slaughter.
Although humans are privileged in Jainism (like other traditions) since only they can achieve moksha but in terms of violence, humans are treated equally with animals. Meaning, killing an animal leads to same consequence (karma) as killing a human being because both are five-sensed beings. This is the argument that Jains make against animal killing so Jains can be seen as PETA's 2,600 year older counterparts who spoke of the rights and the will of the animals but without using the language of "animal rights". Importantly, equating animals with humans was the rationale to stop all violence against all living beings, not an excuse to commit violence against humans of different viewpoint. The famous quote cited by Jains is "Ahimsa Parmo Dharma" that ironically comes from the Hindu epic text Mahabharata and that wishes for nonviolence in action, speech, and thought for all the beings in the universe including humans, animals, plants, insects, earth, water, fire, and air. Let there be no violence against all these living entities!
The issue of eating animals is present in many cultures and not just in India. Killing of horses is a legal issue in America and killing of cattle is increasingly becoming a medical, ethical, and ecological issue, also in America and elsewhere. Similarly, eating pigs has been an issue in Islam and similar "kosher" examples exist in Judaism.
Also, a lesser known fact is the British origin of cow slaughter in India. Beef was not the preferred food of Indian Muslims, even the elites such as the Delhi Sultans and the Moghuls. They ate mutton, camel meat, chicken, fish, geese, antelope and other game. Also, contrary to the popular belief, they ate plenty of vegetable. How then did the converts, who constitute 80-90 percent of the Muslim population, develop a taste for cow?
And lastly, there has been an explosion of op-eds and commentaries on this issue in hundreds of websites and there seems virtually no end to these...from both liberal and conservative sides. Like in the USA, both sides in India are getting enough space to share their opinions in English due to the internet. It can only be hoped that an issue to stop violence, would make all sides more peaceful and nonviolent instead of petty politics that is shadowing the main issues, as always and as elsewhere.