It isn't really shocking if you look at it objectively and see from their perspective for a moment.

A genuine pro-lifer, by definition, believes that abortion is morally equivalent to murdering a newborn, because the unborn is equivalent to a baby, to them.

So imagine how such a person would read what you just said:

It is perfectly fine being against murder for personal beliefs, but to be against giving others the choice to murder is shocking.

It's understandable that the above sentiment would come off like the words of a madman.

Because there is truly no 'debate' to actually be had about whether or not one believes the unborn 'count' as babies, it's completely futile to argue with pro-lifers on that axis.

Nor should one be surprised that they are 'anti choice for others' when itI comes to this, as I am sure you are against others having the choice to murder at will, regardless of whether you wish to murder anyone.

It's like saying that it's shocking that a hypothetical group of people who believe theft is the worst possible crime you can commit, believe in capital punishment for thieves. Sure, it sounds bizarre to everyone else, but it shouldn't be surprising at all that they feel that way, given that they believe.