I guess they're trying to erase Palestinian ~~culture~~

I think you are right (erasing culture is part of a genocide). But why target scientists specifically? To boycott, divest, and sanction (BDS) a country committing genocide, you target what you can. A university can divest from Israeli companies, and boycott their universities through the cancelling of visiting academics, joint research projects, etc. beyond that the university has little direct action they can take.