Wikipedia's job isn't free to be anti- or pro- anything, it's to show facts free from bias, even if you and most other readers agree with that bias.
Of course the facts can clearly show something to be almost objectively evil to anyone capable of understanding them, but it's not for Wikipedia to perform any analysis of those facts - saying "Israel has killed X civilians in attacks which many of their allies claimed were completely avoidable [citation]" in an article featured on the front page is perfectly valid, however a big banner with a Palestinian flag is not as it's a (fair) interpretation of the facts and not simply a presentation of them.