The red zone show in a sat map is the temperature .. no more
Not quite, it can also show some information about the thickness of the cloud and/or the density of droplets+ice within.
while the MTO airborne radar indicates the density of the ice or congestive clouds.
Airborne weather radars are not good at detecting ice, many won't detect it at all.
It is more dense and the cloud is active, the more dangerous it is and of course it will be shown in red on the radar screen meaning the green opposite the only water detection.
This is simply wrong. (added: assuming I understand properly what you wrote, it's hard to follow)
So what the point to show what the flight crew can not seen ??
Because we're not trying to demonstrate what the flight crew saw, we're trying to figure out what caused them to fall out the sky. If this graphic helps by showing something that could be relevant then I don't see the problem.