The problem is that the idea was to strike to break the balance between the protesters and the IRGC. At one point there was a stalemate and the thought process was to strike IRGC and weaken them in order to allow the protesters to push more as long term the state will always win.
However it came to a screeching halt when the army and the police did not join revealing that nobody wanted Pahlavi to gain power back as the local elites decided not to take sides. Then some other countries came to the conclusion that IRGC might decide to go for a suicide bombing and they decided to intervene as the conclusive result would not be achieved and creating chaos was also not an option.
That's just your opinion. Every other group - and a country - in the region knows why the attack was not done.