Sony warranty does not make any sense

Good day everyone. I have just found out that if you buy used headphones, they are not covered under warranty. That is just something i have never faced before as the warranty should cover the product and the end user should not matter at all. At least that's what my gut and previous experience with other used items tell me

Is that even legal to decline warranty service for this sole reason? If they were to say "the headphones were broken by the previous user" that would make 100% sense, but why do i need to even contact the previous owner for all the hassle of contacting sony and then getting those back to me? I have the xm4s with battery drain issue and it is just unbelievably stupid.
Thank you!