There are a lot of factors to consider before using a whole plane parachute systems. The aircraft in the picture is a small one. For the size of that Cirrus aircraft, a 40 kg safety equipment is a viable safety option. But when you scale it to a big commercial airplane like a 737, you’ll have to scale the chute and add more heavy parts to it. It would also require more parachutes and deploying explosives and rockets. We are dealing with a big plane that’s cruising at higher speeds at higher altitudes. Which means that you will have to deploy the parachutes faster at high speeds. Also, the airplane structure should be capable of withstanding such heavy loads induced by the sudden deceleration. This ultimately requires more heavy stuffs, which eventually reduces the plane’s payload – the passengers. Overall result is that a complex whole plane parachute system wouldn’t be that practical and economic for the airlines due to the reduced payload and increased maintenance costs. Moreover, most of the air-emergencies occur only while landing and takeoff. So it wouldn’t be a wise choice to put parachutes that could only help the airplane while cruising.
