Why, it was like reading about France and the French, before the ever memorable and blessed Revolution, which swept a thousand years of such villany away in one swift tidal-wave of blood—one: a settlement of that hoary debt in the proportion of half a drop of blood for each hogshead of it that had been pressed by slow tortures out of that people in the weary stretch of ten centuries of wrong and shame and misery the like of which was not to be mated but in hell. There were two “Reigns of Terror,” if we would but remember it and consider it; the one wrought murder in hot passion, the other in heartless cold blood; the one lasted mere months, the other had lasted a thousand years; the one inflicted death upon ten thousand persons, the other upon a hundred millions; but our shudders are all for the “horrors” of the minor Terror, the momentary Terror, so to speak; whereas, what is the horror of swift death by the axe, compared with lifelong death from hunger, cold, insult, cruelty, and heart-break? What is swift death by lightning compared with death by slow fire at the stake? A city cemetery could contain the coffins filled by that brief Terror which we have all been so diligently taught to shiver at and mourn over; but all France could hardly contain the coffins filled by that older and real Terror—that unspeakably bitter and awful Terror which none of us has been taught to see in its vastness or pity as it deserves.
"Good" is subjective. In any conflict where blood is shed and lives are lost, we might feel pity for those who suffered and died, regardless of what side they took in the conflict - or if they were part of no faction, and simply at the wrong place at the wrong time. The French Revolution of 1789 is no different; for every account you see that decries the essential unfairness and manifold cruelties of the revolutionaries, there is another that reminds us, as Mark Twain did, of the terrors of the Ancien Régime. In popular culture, the Revolution has taken on an almost mythic stance, an inspiration for a thousand revolutionaries and as many for those who decried the bloodshed and terror. For every speech Mark Twain put in one character's mouth, this is another by Charles Dickens in A Tale of Two Cities, or Baroness Orczy in The Scarlet Pimpernel.
So it is rarely the case that the French Revolution is seen as objectively "good." What it was is impactful. It shook the thrones of Europe, and it has become one of the most studied revolutions of the late modern period. As a period of tumult, it became both quite a popular setting in the late 19th/early 20th century, and a continuing point of discussion - because the French Revolution became, in the popular consciousness, sort of the blueprint for many of the revolutions that came after, in idea if not always in fact.
American sympathies in the 18th and 19th centuries in particular tend to be a little more divided than those in continental Europe, because the French Revolution happened only 20-odd years after the American Revolution, and the conflict polarized the young Republic along lines both practical (in terms of treaties, France having been a major ally without which the US would not have achieved its independence) and philosophical (the pro-democratic moves aligned with some of the ideals of the United States). If you read Thomas Jefferson's take on the French Revolution, for example, you'll find an early enthusiasm for the revolutionaries that became tempered after the fall of the Bastille.
The French Revolution tend to be viewed as a good thing because of its heritage. In Europe, it marked the completion of the Enlightenment. The juridic heritage is really important too. The Declaration of Human Right and Citizenship is the first universal list of rights. The Revolution is directly linked to the Empire, and its juridic reorganisation: the civil code, which is a model of legislation that is present all around the world. Yes the Revolution was brutal, yes a lot of people died. A lot of people also died because of the will of European monarchs to maintain the Old Regime, and the total inequality that came with it. I saw your post yesterday. It’s important to realised that the Revolution wasn’t started with that result in mind. If you look at the list of grievances gathered just before the General Estates, people wanted a more fair tax repartition (at the time, only the third Estate paid taxes, the nobility and the clergy, who had most of the wealth, paid almost nothing), equal access to State Employment, the end of the arbitrary regime (cf. Lettre de cachet which enable the kind to imprison anybody, at will). The king still hold a good amount of popularity among the population, and most people from different Estates and social class didn’t wanted something other than, at most, a constitutional monarchy. It was a Revolution made mainly by the bourgeoisie, they wanted to pay less taxes, and access to power position in the army and the Administration, because they felt that the nobility was incompetent for the most part, and holding to its privileges. The masses were often instrumentalised by the kings opponents (see the the Day of Tiles in Grenoble on June 7 1788). Finally, in France, the Revolution is « commemorated », which is different of celebrating. A commemoration is different from a celebration. During a commemoration you remember what happened, in good and in bad. The French Republic will never say that the Revolution was a bad thing in itself, because it is the daughter of that period (the DHRC is even part of the Constitution Bloc). But it may also acknowledge bad part of it, like the terror and the wars. Nothing is black or white, everything is a nuance of grey.