This more than anything else
There's also gameplay aspects to FFYL. If your shields go down, often it's better to charge at an enemy head-on than hide. If you run for cover and as you get there you go down, you're fucked. Most enemies die really quickly so if you get in their face and they take you down, at least you'll have your gun in their torso so you can get a second wind before they run and hide.
a Nexus a day keeps the apple away