The 2008 Mumbai attacks were scouted by US citizens who had Pakistani origin: https://en.wikipedia.org/wiki/2008_Mumbai_attacks

So the Indian authorities are very much interested to find out if you have any South Asian ancestry. If they see such history, the evisa is likely to be rejected and you will be asked to apply for a regular visa.

India is not alone in this process, the US also asks you quite intrusive questions about your past, including any other/past citizenships.