We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Adams wasn't referring to the American system when he was talking about democracy. However, Franklin was when he replied to the question of what sort of system did the Constitutional Convention arrived at, "A republic, if we can keep it". It was known that republics burn themselves out just like a democracy but took great care to include features that caused other republics to fail such as prohibitions of spending one citizen's money for the benefit of others. They knew that when the government can take from one to give to another, that it devolves to what Rome had and what we have now and that the end is almost assured in that situation.
I think H. L. Mencken said it best:
"The government consists of a gang of men exactly like you and me. They have, taking one with another, no special talent for the business of government; they have only a talent for getting and holding office. Their principal device to that end is to search out groups who pant and pine for something they can't get and to promise to give it to them. Nine times out of ten that promise is worth nothing. The tenth time is made good by looting A to satisfy B. In other words, government is a broker in pillage, and every election is sort of an advance auction sale of stolen goods."
The quote is dated, and keep in mind that in that day a democracy and a republic were known to be different forms of government, unlike today where the difference is largely blurred in the common definition.
Our system of government leaves a lot to be desired but it is better then all the other options. No form of government "lasts long". Of all the modern nations how many really have a form of government that has lasted longer? Certainly ours will fail too and the current political leaders seem hell bent on making that happen sooner rather then later.