There are two assumptions that people in these discussion make 1) If 30% of the passengers leave their devices on today, leaving 100% of the devices on won't c

There are two assumptions that people in these discussion make 1) If 30% of the passengers leave their devices on today, leaving 100% of the devices on won't cause any increase in problems, and 2) If something happens it's either a) nothing, or b) the airplane falls out of the sky. The fact is that an airplane is an incredibly complex machine. Instrument failures happen all the time, and pilots deal with this (they have redundant instruments and alternate procedures they can follow). If some of these problems happen due to interference from electronic devices, that's pretty much impossible to verify.