If that satellite info is so reliable, why it can not pin point where the plane crashed? Why no debris was ever found?
The plane could have landed in any part of muzzieland under control of jihadists. That includes ISIS (Iraq & Syria), Yemen, Afghanistan, Waziristan province in Pakistan, etc.
The satellite was designed to relay messages from airplanes, not to track them. However, Inmarsat engineers were able to deduce the arcs from the time delays observed in the satellite's hourly pings of the airplane's satellite transponder. (The bad guys had turned off the systems that use the transponder, but they forgot to turn off the transponder itself.)
The ping delays determine the plane's the distance from the satellite, which hangs several earth diameters above the Indian Ocean. The arcs are the intersection of a distance-determined imaginary sphere with the earth's surface, further narrowed by how far the plane could have gone, given time and fuel. The north vs south is a somewhat iffier analysis, based on small frequency shifts in the ping replies, which indicate the plane's speed towards or away from the satellite. But the arcs are pretty iron-clad.
Engineering, not whack-jobbery, IOW.