Part of the Indian culture to suck up to the majority race in power. If they were in the US, their partners would be Caucasian. These Indians tend to look down on their own kind and hope to climb up the social ladder by either marrying into the majority race or currying favour with those in power.
These are also the Indians favoured by the PAP, for the simple reason that less ethnically conscious Indians are less likely to serve sectarian interests and rebel against the PAP's racially divisive policies: Tharman, Vivian, Dhanabalan, etc.