Totally agree with Blacksheep, it's important we find out what on earth distracted the crew to the point of not spotting something as basic as decaying airspeed... There are always lessons to be learned.
If it turns out that it is the crew chit-chatting to each other, then I guess yes maybe this really is a case of dreadful airmanship...
If it is something else, like a nuisance warning, it might be worth discussing the current DODAR (or equivalent) methodology. All TREs would tell you they see crews not flying the airplane far more often than you'd think. Most likely when a warning, sound or smell does not seem to match any known scenario. Maybe troubleshooting methodology should include a very clear reminder, right at the onset of the problem, about who is flying the airplane. And part of PM duties should be to remind the PF to get back to his/her instruments if he/she starts getting too involved (not easy if PM is young F/O and PF getting frustrated by e.g. F/O taking too long to find correct QRH section)
I know it sounds obvious and hopefully most of us would do that without having to go through any type of mnemonic. But like I said, TREs see that role separation brake down on a regular basis.
No need to reply with "but this is basic airmanship!". Yes it is. Yes I know that. But yes, continuously improving CRM methodology does save lives.
P