Reagan's approach to Latin America was a touch more brutal than his immediate predecessors, but the disregard for human rights is only really notable for its contradiction with administration rhetoric towards the Soviet Union. The other difference was Congress; for the first time in a very long while, there was serious objection within Congress to administration Latin American policy. This resulted in a number of unsavory projects to limit the amount of information Congress possessed on US foreign policy, the most notable of which was the Iran-Contra affair. As the Cold War eased, so did US policy, opening some space for opposition movements in Latin America. When these movements no longer threatened to "tip the balance" towards the Soviet Union, they could tolerated and even supported to some extent.
This is a really good point. For as much as progressives rightfully excoriate Reagan for his foreign policy toward Latin America, he really wasn't that much worse than his predecessors going all the way back to William McKinley. The difference as Rob points out was Congress. By the 1980s, severe opposition to U.S. foreign policy in Latin America developed for the first time. Reagan was completely unwilling to heed this opposition, even if it meant engaging in illegal and impeachable actions to pursue his policies in Central America.
Of course, we should keep reminding the world how horrible Reagan was; this is especially true because of how conservatives lionize him. But it's also important to note that William McKinley, Theodore Roosevelt, William Howard Taft, Woodrow Wilson, Dwight Eisenhower, and Richard Nixon were all terrible and the other 20th century presidents not all that great.
In fact, one might make a legitimate argument that the best president for Latin America since 1898 was George W. Bush (!) because he was too mired in his inept Middle Eastern foreign policy to pay Latin America much mind. Even when he did notice Latin America, the attention was too minimal to make a difference, most notably in the failed coup against Hugo Chavez in 2002. That's pretty damned faint praise right there, but it shows how singularly terrible the United States treated Latin America in the 20th century.