Yes its fair to point that out, it was extremely hypocritical. In fact, not only did the leaders of the American Revolution justify slavery but most of them actually owned slaves themselves, including most famously Thomas Jefferson, the principle author of the declaration of independence, who was a very rich plantation owner. Virginians like Jefferson and Washington played a leading role in the revolution and in the early United States and Virginia's economy and society was based on slavery. Their dominance ensured that the voice of slave owners was very prominent in the early American republic. There is a really excellent history of colonial Virginia by Edmund Morgan called American Slavery, American Freedom which begins with this paradox- that the same people who endorsed liberty in the revolution lived in a society based on slavery- and explores the development of slavery as an institution and how it became so central to American thought which you might be interested in. Part of Morgan's argument is that the development of a rigid racially based slave system was partly prompted by the fear of a lower class revolt (i.e. an alliance between black slaves and poor disenfranchised whites). This highlights a second point worth remembering- the declaration of independence is also hypocritical since it says that all men should be created equal but the early republic disenfranchised not only black slaves but also poor white men. It was a society built by and controlled by rich privileged white men. As for native Americans, not only were they treated terribly, like you say, but one of the motivations for American independence was a desire to expand more aggressively against the natives. Its worth noting they were not just called hypocrites by us, they were actually called hypocrites at the time. During the war for independence, one of the main propaganda arguments by the British was that these supposed defenders of liberty were all slave owners (not that Britain was really any better of course).

People might tell you that it is unfair to condemn the founding fathers because they were only acting by "the standards of their time" i.e. they would never have condemned slavery because people just didn't do that then, but they are factually wrong. There were many people opposed to slavery in this period (most importantly of course the slaves themselves) who acted politically, made their views known and achieved real victories against slavery. Following the French Revolution, in 1789, there began, in 1791, a revolution in the French colony of Haiti which abolished slavery and, ultimately, won independence for the country and granted equal rights for men (much earlier than they were granted in the US). In 1794 France itself abolished slavery. Ex- slaves were sitting as representatives in the French national assembly in the 1790s. During this period people like Washington and Jefferson were still in power in the US (Washington was the president) so it can hardly be maintained that they were unaware of anti-slavery arguments or even egalitarian and democratic arguments.