Why one and not the other?
Probably it is the predilection of northern europeans vs western asians.
In Buddhism everything is suffering.
In Christianity everything is about original sin.
The only thing really better about Buddhism than Christianity is that they preserved the words of their great teachers far better.
Christianity had several cycles where they modified the bible. Naicia, King James...
The other big thing is that Buddhism is not a religion. It is a path of following the Buddha's footsteps.
Or a pathway to godhood. (in Christianity it would be termed, becoming like Jesus)
In the future, all the religions will crumble.
As we are seeing Catholicism crumble now. (even more so after information comes out about how they have lied to all the people, and how badly)
In the future, we will have people who are spiritual, and seek spiritual enlightenment. They will use all the great texts, and not be beholden to any religion.
I learned about this when I studied the gospels at the age of 13 and concluded at that point Christianity was not for me. Thank goodness! My mother wanted me to become a priest ;)
Why one and not the other? Mostly I suppose because I feel as if I just discovered Buddhism and like any new relationship, it is hard to see the cracks at the beginning.
All part of the same agenda to bring us back to a more controlled version of how things were in the past, with one world religion. Only it won't be like the single religion of our past. It will be a perversion of it. Just as modern electric cars are a perversion of the electric cars we had over 100 years ago.
Hopefully the great texts will survive the coming chaos!