The answer to the topic is really simple: because radar is LOS based.
While fog of war would definitely be cool to sort of force scouting to be done, one of the major differences between MWO and MW4 and partially why radar is somewhat pointless for scouting all comes down to it being LOS based. Targeting info is nice, but the real point to scouting has always been about the location of the opFor, and since radar only works off of what you can see and radar is limited in range unlike visibility (provided you can squint hard enough). This forces radar to take a back seat in regards to that. Different sensor ranges/signal based on variants and weight would be nice, but it still doesn't change the fact that eyesight is the key to determining the location of the enemy instead of radar. Seismic is really the direction you want to take with radar to embolden information warfare.
My suggestion:
Make seismic or some sort of "wallhack" radar a standard part of all radar. Keep it so that you cannot target them, you just get the ping on your map (how it functions currently). Allow ECM/BAP/Shock Absorbance/Sensor Range module to affect it (BAP/SSR module extends your detection range, ECM/SA module reduces your signal). Differentiate the ranges of seismic based on their role/BV/etc, so a Dire Wolf could have no range for seismic sensors (effectively making it have no seismic) whereas a mech like the poor Trollmando could have a lot more range that the average mech. This may not make information warfare a key component, but it would definitely make things more interesting and make radar more important than it is currently.
Edited by WM Quicksilver, 20 August 2015 - 03:21 AM.