Well sure, I agree. But the BBC isn’t taking the moral high ground here. They have previously and will again use the word ‘terrorist’ to evoke an emotional response for international attacks.
Interestingly, on their Bitsize page, they describe the Palestinian Liberation Front as a terrorist group, which is true. The mere fact that they have a page on ‘terrorism’ indicates that they don’t take a moral position against the word, just against calling Israel (and Israeli factions/allies) terrorists - www.bbc.co.uk/bitesize/guides/zy7nqhv/revision/1