Yes, fair points.
I think parts of it are accurate for some of the protestors. I think, as you say, there are different motivations for others, although I think those motivations for all are very rarely motivated by a general dislike / enmity towards Jews.
I think another factor is how intimately the UK state is associated with this whole situation. We controlled Palestine, we signed the Balfour declaration, we washed our hands of it administratively in the face of Zionist terrorism, but politically , in the decades since, we have always been perceived as being at the right hand side of the US when it comes to support, military supplies etc. This is part of the reason why this issue attracts a lot more UK attention than, for example, Sudan or Myanmar.