I have wondered why it was a target
This I can tell you. It was a target because the USS Vinncenes shot down Iran Air flight 655 in 1988.
My understanding is that this act was not officially sanctioned by the Iranian government, but was perpetrated by a wealthy family in Iran who had lost relatives when Iran Air flight 655 was shot down. It was revenge, pure and simple.
I can also tell you that Bill Clinton knows the truth, but because he's a coward, he ordered the investigators to make up some other cause. If Bill Clinton had allowed them to tell the truth, we would likely have had a major crises, perhaps war, with Iran.
He figured we shot down one of their's and now they've shot down one of ours, so why don't we just leave it at that?