How important is it in a relationship for you to stand up for someone?

In my view it is extremely important for building trust .... what else are you having a relationship with that person for??? I mean if the person you are with does not stand up for you then who will? and if you dont even stand up for someone, then why be in a relationship with that person?

I find so many people not willing to stand up for someone in relationships.... its almost like they are left to themselves even if they have people who are supposed to stick by you through thick and thin.... and I wonder what is the point of the relationship? Just for a name

I mean if a boss cannot stand up and support his/her junior in a crunch - what is the point? if a boyfriend cannot hold your hand when you have an operation - what is the point?