There are many, many objectives for which the F1 rules need to account. Competitive balance is one of them. Providing interesting and relevant technical challenges for automakers and teams is another (and was a major driver behind the recent switch to hybrid engines). In addition to those, you have safety, spectacle, cost-containment, logistical considerations, and about a thousand other goals that need to be incorporated. The FIA takes incredible flak for whatever they do because there are myriad tradeoffs between these objectives, and it's impossible to balance them all in a way that makes everyone happy.