They are often not glorified, but in many more realistic game systems, defensive actions exist for a reason. If damage is deadly, or getting hurt leaves you wounded and less capable than you were before, defending yourself (even sometimes at the expense of your own offensive actions) is the best strategic decision.
Some games provide space for characters who build their combat strategy on defensive actions, to the chagrin of storytellers world-over.
So, what do you think? Do they have a place in mobile RPGs? Cyber Knights gives you a Dodge and Cover action whenever you are targeted by an enemy, and I personally use them often (especially on Brutal, where Perma-death lurks). Fun, indifferent, annoyed? What about bad guys who use them against you?