Formula 1 isn't completely scared of change, just look at some of the rubbish rules and format tweaks that have been rolled out in recent years.
For example: try as we might, it's impossible to entirely forget that dreadful qualifying change introduced at the start of this season. Thank goodness it only lasted two races.
As that sorry episode showed, F1 is not afraid of altering something even if it doesn't need changing. Yet on other occasions things are deemed sacred, untouchable, and modern F1 is poorer for it.