I use lightroom where you don't have to compromise on how you store your images or how you want to arrange them.
It's statements like that that tell us that this while you think you know enough about iPhoto, that you actually don't. You can also use iPhoto with images stored as you want, and have been able to do for each version for the past 7 years. Don't particularly recommend it but it is perfectly possible.
Of course, if Lightroom is the correct App for you, by all means use it. But that's a Pro level app costing 10 times what iPhoto costs (and until recently used to cost 20 times). Comparing that with iPhoto is like comparing iMovie and Final Cut or Word and TextEdit. iPhoto is an excellent lossless proceesor (like Lightroom) and Photo Library Manager (like Lightroom) but not all the same bells and whistles as the Pro application. It will even process Raw (like Lightroom). But it's not aimed at Pros, like iMovie isn't, like TextEdit isn't. However, for the family snapper, the person with a point and shoot or even a phone then it's a very good and very capable application and very good value.
What irks is when someone claims to be knowledgeable and isn't.