Why did the BBC refuse to tell the truth about Corbyn?

This Daily Mail article http://www.dailymail.co.uk/debate/article-4590454/Why-did-BBC-refuse-tell-truth-Corbyn.html asks a fair question: Why did the BBC refuse to tell the truth about Corbyn?

You should read the whole piece, here's an extract:

'Let me put my complaint another way. How many of the nearly 13 million people who voted Labour are aware that Jeremy Corbyn has a track record as an associate of Middle Eastern terrorists and IRA killers?'

The problem is that the IRA is not a current problem and for anyone under the age of 40 I question if the IRA is anything other than a name from history. The BBC's uncritical support for the Northern Ireland peace process and vilification of the Unionist cause whilst supporting the ideals, if not openly the methods, of the Republicans in Northern Ireland has set the tone for the young and old uninformed of this country.

Likewise the BBC's institutionally anti Israel bias, allied with the anti Israel sentiment in most UK universities, means that Jeremy Corbyn's calling Hamas and Hezbollah his friends is, to the young, understandable and in accordance with the zeitgeist.

This country is lost: the BBC, the educational system, the agreed narrative is at odds with reality and the interests of the West. It is time to get out of the UK, if they want to destroy it then why should I stay to fight them.