These reasons have been debunked.

1) The population register explanation cannot account for the varying rates of deportation across the country. Some provinces had deportation rates as high as 80%, while others were closer to 20%.

2) Informers certainly did exist, but that alone would hardly explain the difference between deportation rates in the Netherlands and elsewhere in Western Europe. Also, since the identity of the Frank Family informer is unknown, we probably shouldn't speculate on that person's motive.

3) ID cards cannot explain the higher rates of deportation in the Netherlands for the same reason as the informers explanation in No. 2. Other countries had ID cards as well.

The best explanation I've seen deals with varying rates of partisan activity in the Netherlands. Long story short, the SiPo was responsible for anti-partisan activity in the Netherlands. Deportation rates strongly correspond with SiPo activity. At the same time, resistance partisans also did a lot of the leg work in hiding Jews. So the argument is that where the SiPo went in to combat partisans, they also found hiding Jews. So higher rates of anti-partisan activity in the Netherlands correlates to higher rates of deportations. Its actually somewhat ironic, if you think about it.

Source (PDF warning): M. Croes, The Holocaust in the Netherlands and the Rate of Jewish Survival