Khomeini might as well be called bogeyman back in the day. He was
not popular in the West, to say the very least.
As I recall it, the first worry signs came from the extreme conturbation of the movement he led in the late 1970s and that took power in Iran. The same one who kept about hostages in the American Embassy for well over a year.
Then there was the war with Iraq, famous for the "martyrdom" of tied Iranian children sent to find land mines. And it went downhill from there, to the point that Saddam Hussein was seen with some sympathy for being at war with Iran.
Even in those early days it was plain to see that post-Shah Iran was under the rule of a draconian, strictly theocratic regimen. One that raised Khomeini to such exalted levels of authority that even Brazilian authorities were instructed at one point not to depict his visage, in apparent imitation of a similar demand made by Muslims regarding Muhammad.
If Khomeini had qualities that went anywhere beyond being a voice against the Shah's oppressive regimen, those were never at all apparent. He was a theocrat, plain and simple.