I've said it once and I'll say it again.
A religion's success is dependent on the ability for followers to rationalize anything.
Islam and Christianity are no different in this regard.

If there is no major conflict with the nation, Muslims will not pay attention to those parts of the book.
When a conflict comes up, they will go into a religious nationalism of sorts and start using scriptures like that to rationalize.

The most true thing about religion ever in any scripture was that Old Testament bit about "a time for this, a time for that" and whatnot.

__________________
"It's never over... BOY!"
The Tall Man, Phantasm III