We all have very different and very valid reasons for doing so.
But ultimately, the underlying reason beneath all those motives is that we feel rejecting them serves us in some way.
Some aspects of ourselves that may resist others stem from protector parts within us. At times, we might mistakenly believe that denying, suppressing, or rejecting what we perceive as unwanted is the path to achieving what we truly desire.
This includes unwanted things that relate to our ancestry.
But it doesn’t actually serve us at all to be doing this.