Yes. Holding the civilians in the Embassy (their were few diplomats there at the time) was a mistake.
In the past, the U.S. removed a democratically elected leader from office in Iran and replaced him with the tyrant Reza Pahlavi. Thug Pahlavi was educated in the U.S. and used Iranian oil revenues to pay off the CIA. The CIA used the money to fund its secret operations (since Congress requires the CIA to report how it spends all funds it receives from Congress, the CIA needs alternative sources of funding for secret operations).
By the time Jimmy Carter had become President, the Iranian people had become angry with Punk Pahlavi for his fascist policies, lavish lifestyle, and disrespect for Islamic culture. The CIA deliberately failed to report the public hostility toward the Shah to President Carter, who was unaware of the potential revolution being pursued by Iranians. By the time Carter learned of the bad situation in Iran, it was too late to resolve the crisis without bloodshed.
When the Ayatollah Khomeini was set to return to Iran from France, both the French Secret Service and CIA were present. They could have prevented the Ayatollah's return one way or another, but President Carter had Khomeini escorted safely to the airport for his return to Iran. Carter removed Pahlavi to allow for a civil and peaceful change of power from Pahlavi to the new Iranian govt. Not that the change went without bloodshed, however.
Iranians should have welcomed Carter's role in the removal of the Shah, but instead they were angry that Carter allowed the Shah to remain in power for so long. Iranians should have been pleased that the CIA didn't cause the Ayatollah to meet some "tragic fate" in France, but Iranians failed to appreciate it.
President Carter was the first President in recent history to go against U.S. interference in foreign affairs, but the Iranians didn't appreciate this fact.
When Iranian college students climbed the walls of the U.S. Embassy, it was planned as a peaceful occupation of the exterior grounds of the Embassy to attract world media attention to the plight of Iran and to express their fear that the U.S. would invade Iran to install another dictator. Carter had no such intention.
However, a small group of armed Islamic extremists had infiltrated the student's group and raided the Embassy to hold the Embassy staff hostage. These thugs then used the hostage crisis to force Ayatollah Khomeini to abandon his own plans for a Democratic Republic in Iran, and compelled him, through manipulation, to take a harder line. These extremists were traitors. The fact that they would move against the Ayatollah proves that they are not good Muslims, but heritics. One of those traitors is Ahmadinejad. He was one of the radicals who pushed for a totalitarian dictatorship in Iran.
Iranians should be grateful that President Carter was a Christian man of peace who chose not to retaliate against Iran for taking hostages at the Embassy. Many Americans still regret his decision to resolve the matter peacefully. In fact, it ruined his Presidency and place in history.