There is a trend toward ultralight backcountry travels, but you should always take what you need to survive, albeit in the lightest form you can find it. Trimming straps is no big deal, but not taking a locating device certainly is. I'll bet those locating devices weigh mere ounces.
Some people think there is safety in numbers and others just plain think they are resourceful enough to deal with any adversity.
There is a certain amount of parental anger on this thread from those of us who are asking; "how could they have been so wreckless?" watching the poignant vigil by their family members.
Then we question how the climbers could have placed themselves in such jeopardy...not giving pause for any rescuers who might be called in to find them.
Some of us were angry with Mr. Kim for setting out with his young family into uncertain territory in poor weather.
It's just a human condition - helplessness and grief.