Sure, it had a nontrivial effect. But it also happened in a time when Stalin and Churchill were still alive, there were 6 billion people fewer on the planet and the first antibiotics and transistors barely entered production. Korea was poorer than Ghana etc.
It is 2026, three generations have passed, and not everything can be explained and excused by a 1953 event forever. But it is convenient for autocracy advocates in general.
It reminds me of the worship of the Great Patriotic War in Russia. Again, as if nothing that happened later matters.
It is a bit like explaining the Communist coup in Czechoslovakia (1948) by the Western betrayal at Munich in 1938. It was a factor. But not The Factor. Just one of many.
In case of Iran, there, too, were other factors at play. The general drive of the Shah to be the Iranian Atatürk-like Modernizer, which clashed with the conservative rural population. The abilities of Khomeini, who pursued his goal of overthrowing the monarchy with absolute zeal. (Would Turkey be nowadays a modern state if Atatürk himself faced a similar opponent?) Willingness of France to shelter Khomeini and willingness of some Western intellectuals to fawn over him. Naivete of the Iranian Left that joined Khomeinis movement and hoped to come up on top, only to eventually get slaughtered for being "enemies of God".
Etc.etc. It is somewhat intellectually lazy to just drag out Mossadegh and leave the conversation, like GP did. It also masks other unpleasant facts.
For example, in my opinion, the Western intellectual class of the 1970s made a serious mistake by supporting Khomeini and cannot even bring itself to acknowledge it. I think this was at least as consequential to the eventual birth of the Islamic Republic as the Mossadegh coup. But the more people talk about the latter, the more they tend to forget about the former.