I don't mean to sound overly cautious, but I think it's a bad idea. People really should get the hang of putting on the vest at least once and getting outside with it on. There's all kinds of studies that show people who have at least done some practice drills for emergency situations (at sea, land or in the air) are far more likely to come out alive. Of course, the drills are chaotic and no fun. But what do people think the real thing will be like if something happens?... It will be the one's who have put some thought ahead of time in to surviving that will more than likely do just that. I respectfully disagree with the folks who think the trade off is worth it just so they aren't uncomfortable or inconvenienced for a few minutes. People need to know how and when to put the vest on, get out to the deck and get their a@@@@ lined up for the life boats. Would it really be ok with any of you if your kid's schools stopped doing fire drills and just had a quick lecture instead on what to do if the fire alarm goes off?
Last time I flew back from a cruise on ATA, the copilot came in to the passenger seating area before the flight and firmly but politely stated that he wanted everyone to put down their reading materials, electronic crap and whatever else and LISTEN to the flight attendent's standard emergency pre-flight instructions they always read. When she was done, he gave us some additional safety info. I think some people were kind of taken by surprise but I thought it was great. THIS was a guy I would want flying if there was an emergency on board...minor or severe!
The no life vest thing will seem wonderful until something happens...Sorry, it's only a matter of time. It may not be something large scale, but there will be an event when it will be called in to question why people weren't instructed on vest use. Everytime we let our guards down when it comes to safety or security, it always comes back to haunt us...EVERY time.