Nobody has said that phones are a major risk compared to all of the other risks a plane has to deal with e.g. weather, maintenance, pilot experience. Only that they do represent a risk and the status quo represents the most reasonable way to manage it.
What evidence do you have that stricter enforcement is warranted ?
And yet, the status quo dictates employing people to throw out water bottles you purchased at the duty free after already having been screened for it yourself (and probably screened the store's inventory as it was coming in). And consider nail cutters a deadly weapon.
I did not read the GP to say that stricter enforcement was warranted - just that it was not in-line with how other controllable risks associated with passengers risks treated.
The rule can very easily be broken which suggests that it is useless. They either have much stricter enforcement or none at all.
The comparison with weather conditions is problematic since there is no way to control the weather while you could introduce a detection system and severe punishments for cell phone use.