iMovie is a software that anyone can use.. students for a project or fancy presentation, pros who want something quickly and simple or a person that does not know how to make videos but need to.
As all the Apple software, iMove is user friendly. You insert a thing by dragging it, you delete when you press delete.. pretty simple and fast.
You can also add credits and text really easy.
If you want to make some cool and elaborated audio mix, you should be forgetting about iMovie.
You can't also put two videos in the same frame, like you can in Final Cut Pro. Same thing with photos.
Exportation is really, really slow. Even though you have a lot of options, all of them take a long time.
More effects could be added.
You cannot expect iMovie to be a pro video editing software because it is not. I would recommend it for students or small businesses that do not need a lot of effort in their videos. You can make a good video but not a professional one because its lack of features.
Sometimes we make videos about the events we make: conferences, courses, certifications, symposiums.. and since it is really easy and fast to ouse, it helps us.
Quality of exportation is good or you can upload it directly to YouTube.
Exportation is really slow even if the video is not that long.