I'll use an emoticon next time, so you won't have to suspect. Of course it wasn't meant as a comparison. Fewer bullets flying about, not more per second is what I see as safer. Frankly I don't care if they patrol in Leopard tanks

if it gets that result, but I'd imagine that just as this guy went ahead when he knew armed police would respond, having cops with bigger guns wouldn't increase the deterrent. I'd suspect the reverse in fact, that anyone with a plan would arm themselves to meet the SMG carrying cops.
Just promise me your MP5 guys will hit only the bad guys and do it fast, because I'm sure the better armed bad-guys won't be better shots than they are now.
Pure speculation about the air marshals but I'd bet they discovered the danger to the airplane wasn't appreciably lessened (and airframe experience and designs have improved sinece earlier explosive decompression days), and concluded the officer's effectiveness would be improved without adding to the overall danger. Part of what I see as problematic about such incidents is that police have few alternatives, and that the handgun is really a war-maker's weapon, not a violence-stopper's tool. All sorts of clever devices from bean-bag guns to tasers have been invented to be that tool but none has yet moved the pistol aside. When they had to, authorities did look at making pistols safer and still effective on planes. You could sell an awful lot of 2012 Model Peacemakers if you could get such a police-oriented redesigned pistol right. But I've not heard of anyone trying anything but larger calibres, tighter groupings and centre of body mass stopping power.
It's no knock on the NYPD officers involved that what we just saw came from that approach. I can't believe we can't do better.