Today, when I translated 'por respeto a alguien' as 'out of respect for someone', a couple of my students expressed extreme surprise at the word 'out'. Of course, I had never thought about it before, but, yes, they got me thinking. They were right in saying that it didn't make sense to them.
We use 'out' as the opposite of 'in':
I walked out of the room in a hurry.
He threw the ring out of the window.
Or to mean 'none left':
We've run out of coffee.
So, if anything, out of respect, they reasoned, would actually mean no respect.
I couldn't really explain why that wasn't so other than it's a fixed expression. Another frustration.
'Out of' in this phrase actually means 'because of'. Apart from respect, we can also use it with other words of feeling or attitude such as curiosity, interest and pity.
Out of consideration for her sister, she refused to go out with him.
She stuck by me out of pity, and not because she agreed with me.
Out of respect for their Muslim friends, they didn't serve any pork.
I went to the concert out of sheer curiosity rather than anything else.