Porting COD to Switch is much less investment than porting COD from PS3/360 to Wii, yet that was done several times and was profitable.
More demanding games than COD have been ported, so the failure squarely lies with Activision.
source? i think you are very wrong in this, my opionion is that they need a hardware which is max -10% then the next lowest hardware to get the ports from technical stand of view and the next point would be that they need good hardware sales (which they have) to get out small sales from ported games like bf, cod or whatever.
if it would be profitable and possible every publisher would port every game to switch.