I expect that general anxiety about anti-Semitism is driving this. Like it or not, condemnation of Israel comes with certain baggage, and as can be seen on campuses throughout the Western world, criticism of Israel can turn into anti-Zionism which then turns into anti-Semitism very quickly. The lines are very thin. The business world is very risk averse, and coming down on the wrong side of this particular debate can have a whole lot of consequences. Beyond that, of course, Alphabet is a business, not a society for activists, and while it may tolerate certain kinds of activism that may not be perceived as threatening the bottom line, right now, criticism of Israel is just a step too far.