The current layout of the Boeing fuel control switches has remained the same for 70 years - literally generations of pilots know and use this layout.
The potential of a redesign introducing undesirable unintended consciences is very high - especially if it's a knee-jerk response. Something like this needs to be carefully and thoroughly vetted before it sees the light of day. For example, requiring the thrust lever at idle - what if the lever gets jammed somehow and can't be moved to idle? Requiring both pilots to take an action - what if one pilot is incapacitated?
As I understand it, Kegworth both pilots agreed on the engine - it's just that they were both wrong.
I think the first step is to better educate and train the pilots that there is almost never a reason to rush shutting down a turbofan engine. Even with an engine fire, the bult in protections give you minutes to take action, not seconds. Was there some reason (that we don't yet know about) that caused Jeju to 'rush to judgement' and shutdown an engine quickly? Or did they just panic, and get it wrong?
There are lots of ways a panicked pilot can crash an aircraft - shutting down the wrong engine is just one. Maybe the answer is to get pilots to not panic?
Things like EICAS/ECAM have made it far easier to correctly identify a malfunctioning engine - are pilots being appropriately trained to use that?