Formula 1 is a sport. The game is about building the most performant machine within the constraints of the rules. There is a ton of technology that is prohibited in F1 (traction control, automatic gear shifting, ABS, etc) that has been part of road cars for decades. Rule changes tend to relax the constraints from time to time for some specific reason: such as better safety, better spectacle, or cost reduction. KERS (with its driver-controlled boost button) was introduced in 2009 mostly as an attempt to facilitate overtaking, since car aerodynamics had become so sophisticated that a car following another one would get a significant drop in downforce due to the turbulence of the car in front. On the other hand, the 2014 rules appear to have been enacted mostly to help teams lower their running costs.