As well as ( in my opinion ) of it being a mainly religious issue as with everything, it's becoming a right v left issue.
I've no doubt most of the Jewish who are against Netanyahu will be left wing.
I think for many in this debate, they view Israel (Jews) as western, white and affluent / privileged. They view Palestinians and wider region (Muslims) as non-western, non-white and not affluent; ergo oppressed, by the west.
There's been some interesting points put forward about why people would focus on this issue, such as awareness, the UK governments role / ability to influence. I can see parts of that but don't think it explains the huge inconsistencies in approach. Certainly not for the organisers of the demos and many of the more engaged activists. I still think for them the perpetrator is more important than the victim.