During that time, many Jews were not even Zionists. World War II forced many Jews to flee. Israel wouldn't have had a huge influx of Jews if Jews didn't feel insecure in Europe at that time. Otherwise, more would have stayed in Europe. Christians didn't really want to stay in Europe let alone Jews. People were fleeing. Immigration by Jews increased with the holocaust.
Judge orders Jerusalem Gay Pride attacker to undergo psychiatric evaluation (Haaretz)
from the article: It's wrong to suggest Israel was direct result of Holocaust