I'm sure most of us would rather avoid an altercation when that is possible. Sometimes, in a life-threatening situation, one does not have the choice to avoid it (even by running). Including atemi in your aikido is a good way of trying to preserve your life and possibly your family's/partner's - and therefore "training for life".
I never have the option to run, unless I am attacked by an inanimate, immobile object. I dont have it in the Nike-do, so I put it in the aikido. Dont worry, I know how to reach out and touch someone. I'm a pretty big girl who has been around the block a few times. I'd still rather not fuck my hands up any more than they are with making sure I can punch through cinderblocks. I can hit hard enough, when I have to.