Is there any reason why someone would not get a personal exemption on the NJ tax form?

[TomD8]

Here's one reason:

If you were a member of a domestic partnership that was registered in New Jersey on the last day of the tax year, you can claim a $1,000 personal exemption for your domestic partner only if they do not file a New Jersey Income Tax return.

https://www.nj.gov/treasury/taxation/njit2.shtml