There are a few men out there who see women as nothing more than sex objects and baby factories. For a woman to openly reject that role challenges their male chauvinism. They don't actually care that she reproduces, but they don't want her to influence other women to think they don't have to settle for the role they've been assigned. That's why one threatened her with laryngectomy, which obviously has no connection to reproduction.

also, some people just like to try and be as hurtful as possible, regardless. especially on the internet.

I've certainly been guilty of lashing out at someone with whatever I felt might cut deepest. being impotent to resolve your (technically unjustified) rage can lead a person down a dark path.

According to an older family member, me and my girlfriend's decision not to ever have children was "destroying the white race" and was going to result in "muslims taking over".

There's really nothing more wonderful than ignorance backed by fear. or fear backed by ignorance.

I can think of a few reasons, mostly that it implies[] criticism the same way most abstinence does. But you should check out the reaction to the previous BBC coverage in my other comment to get an idea of other reasons.

[] is perceived as implying, i guess

Because society as a whole spent resources on you to educate you and turn you into productive member of the society.

Its your responsibility to repay that debt by reproducing.

This is one of the strange explanations I usually get.

That's actually not a strange argument. It's semantically identical to the widely-held belief that the benefits of order, safety, and education granted by the government morally obligates one to pay taxes.

One could argue that the people making 'that' argument should probably not be reproducing ;-) !