Gershom Scholem wrote an article about the Star of David where he said that
"There is no reason to assume that it was used for any purposes other than decorative".
Uri Ofir wrote a research about the origin of the Jewish Magen David where he said:
"I didn't like the scholarly version presented by Gershom Sholem that every nation needs an emblem and that's why we adopted the Magen David (Star of David). Actually he didn't suggest any solution as regards the origin of the Magen David (Star of David). Beyond that I was convinced that on the level of values it's impossible to educate on the basis of opinions such as this".
These two excerpts led me to assume that Gershom Scholem didn't like the fact that the Star of David was chosen for the Israeli flag but then I found an article by Mark Verstandig who wrote :
"Gershom Scholem, the great Jewish scholar JUSTIFIED choosing the Star of David for the Israeli flag because the Jews were murdered under this sign. This sign has been sanctified by suffering and has become worthy of illuminating the path to life and reconstruction".
I think that the place of the Star of David is on the Israeli flag due to three main reasons:
1. The holocaust (as Gershom Scholem thought)
2. Its origin from the tabernacle Menorah (as Uri Ofir thinks)
3. Most of the Israelis think that's the place where it should be!