In history doing anything, including nothing can be extremely dangerous.
Rome had stumbled from political crisis to crisis for decades and in a system that could not be reformed due to social/political inertia something had to give until somebody came up with a workable solution.
Caesar was a radical who saw major opportunities and grabbed them, just as Brutus believed everything could nominally remain the same if the wrong people would go away.
They both represent the wrong answer to a problem neither understood. Caesar believed he could become the dictator of Rome and restore order, Brutus believed the genie could be put back into the bottle and the system would revert to whatever glorious period of perfection he was deluded to believe had existed at some point.
Brutus and the liberators could have bought the republic a reprieve, but sooner or later the system would come back for another cycle until either somebody made huge reforms or introduced personal rule.
It's hard to gauge if Brutus truly was an idealist or merely somebody who tried to put a halt to the ambitions of Caesar and hoped to get at least some of the perks of these actions. If Octavian and Mark Anthony had ever learned a key lesson it's that it pays off to show respect and pardon the defeated side. To pay tribute to Brutus and portray him as a noble Roman went a long way to ease things in the aftermath of the Civil War.
In the end Octavian as Augustus brought a much needed hotfix to Rome's problems and I seriously doubt that Brutus and the liberators would have had the foresight to implement any kind of solution other than pine for some long lost ideal period of the Republic and brace for the next political crisis.