Zionism was not started by Ottoman Jews, which were a very, very small minority in Palestine. The grandfather of Zionism was an Austro-Hungarian, Theodor Herzl. Before that there was a proto Zionist movement the Hovevei Zion which was created in response to pograms in the Russian empire. The Zionist movement was entirely created as a response to the treatment of European Jews by European powers.
Living under sharia law and being treated as a second-class citizen (which all non-Muslims were) certainly was not ideal for Palestinian Jews, but hundreds of thousands of European Jews did not start streaming into Palestine because of that.
Time zones are part of it, but also daylight savings is a real pain in the ass. And like you said it gets particularly complicated when you’re dealing with a system that deals with these things as an afterthought, which seems to be a lot of older libraries for time. For instance, the Java date utils are a nightmare and are now considered semi deprecated replaced by a new java.time api. That is, of course, no help for the ridiculous amount of things that depend on these stupid date utils and no one wants to spend the dev hours to refactor.