Oh wait ...
Because, people don't seem very happy about the result of the "success" of the revolution. Not at all. They also seem desperately poor, even if relatively successful. Only the massacring mullahs they brought to power look rich at all.
In fact now most people seem to wish that the evil oil companies would have won the revolution. Because, of course, they would have employed and helped the population.
Take for example the iconic photo:
https://substackcdn.com/image/fetch/$s_!K5Yp!,w_1456,c_limit...
Apparently the girl on the left was executed by the mullahs for protesting and the girl on the right was forced out of the country. Doesn't sound like this "overthrowing the dictator" was much of a success at all ...