IF the accident was caused by TOGA buttons not providing the expected result, it does seem a strange decision process by Boeing to disable the function at a point in the flight where if it is selected it's obviously an oh #hit moment.
I mean the take off part of the TOGA is pretty standard, most flight start like that, and you can understand there maybe hundreds of systems and functions that are checked, up to and including the handbrake being off and the in flight service trolleys being parked properly - before all hell lets rip.
but if the plane is in the landing phase and TOGA is pressed that isn't something open to a committee of electronics to discuss is it? PIC wants to get the hell out of here, lets go.
I can understand it would be disabled once airspeed drops below 50kt or so to avoid speeding into the terminal, but it seems to me Boeing added an extra rule to prevent inadvertent use, that may well be very 'advertant'.
(I'm not saying the crew shouldn't check the aircraft was responding as expected)