No-one can possibly defend the murder of civilians, especially children and even babies - nor attacks on innocent, peace-loving people who are attending a music festival.
No-one, except for racists who work for the genocide of that population.
But this doesn't mean that we should start saying that the organisation whose supporters have carried them out is a terrorist organisation, because that would mean we were abandoning our duty to stay objective.
That makes it sound as if the Hamas was a regular, military organization with legitimate goals, which eventually settles their dispute at the negotiating table. And I think that's giving a false picture of that organization. But let's hear what they have to say about themselves:
Quoted from article 7:
"The Day of Judgement will not come about until Moslems fight the Jews (killing the Jews), when the Jew will hide behind stones and trees. The stones and trees will say O Moslems, O Abdulla, there is a Jew behind me, come and kill him. Only the Gharkad tree, (evidently a certain kind of tree) would not do that because it is one of the trees of the Jews." (related by al-Bukhari and Moslem).
Quoted from article 13:
There is no solution for the Palestinian question except through Jihad. Initiatives, proposals and international conferences are all a waste of time and vain endeavors.
These people (Hamas, not Palestinians) see it as their religious duty to kill all Jews.
I think the BBC's position makes sense in most conflicts, but not in this one. They probably just try to appease both sides, with an explanation that sounds reasonable, if you don't look too much behind the curtains.