The inlet screens we used in the USN on F-4's and A-7's caused surging,false indications,and were a nightmare to inspect and maintain.I remember the poor NDI guys inspecting every weld on every square of mesh screen! probably some of the reasons airlines don't use them.
Airlines in a rush = money - or a bloke dies? Hmm, tricky call, that. Intake gaurds. Stops you going in and also stops other big things going in AND if you paint them bright red reminds anyone approaching the aircraft that the motors are running!!! The RAF Nimrod fleet use 'em all the time. OK, so maybe a Spey doesn't move as much air as a CFM - but they are still a bloody good idea! You won't stop people going near running donks no matter how many edicts are issued so the next thing is to try and stop them going down the intakes.