I think much earlier in my life I would look at someone who was heavily modified and ask myself “why?”. I don’t ask why anymore, I just try to accept that this is who they choose to be. I feel like if you can answer the “why?” question for any form of body modification large or small you can use that same answer for anything.
Why do I have my piercings, tattoos, scars, and implants?
Because this is who I am. This is my body and this is how I choose to express ownership over it. This is my chosen aesthetic identity.
If you need a better answer than that about any form of modification then I think the issue is really your perspective and how you react to someone else’s choices. Don’t try to understand someone else’s motivations, try to just be accepting of their personal choices. Just as you might feel offended by people questioning the choices you express with your body, others feel the same way.