For example, a major flaw in iTunes (which it still suffers from) is that it didn't automatically pick up files you added to your music directory. You must manually "add to library..." every time you add music to your computer. EphPod, on the other hand, managed to stay in sync automatically.
Another historic defect: By default, iTunes would sync with an iPod automatically when it was connected to the computer, and you had no opportunity to stop it. There was a checkbox in iTunes's settings to turn this behavior off... but it was HIDDEN unless an iPod was connected (obviously too late to prevent the syncing)!
The profound defectiveness of this design became apparent when people replaced their hard drives and plugged their iPod in... only to have all their music blown away when iTunes "synced" with an empty library.
Another one that still exists: When a file goes missing, you don't know about it until you try to play it; it's not indicated in the UI (again, because iTunes lacks auto-syncing of your library to files on disk). And when it happens, you obviously want to troubleshoot it. The first question you have is, where does iTunes think the file should be? Guess what: You can't find out. It inexplicably won't show you the path it expects the song to reside at. You can get that info if you right-click on a song that DOES play; but if it goes missing, iTunes refuses to show you where it's looking for it.
Then there was iTunes's inability to separate identically-named albums by different artists ("Greatest Hits," anyone?). I haven't checked this lately, but it was a problem because Apple apparently couldn't figure out how to group by two criteria.
Also, if the library DB gets corrupted and you need to delete everything and re-add it, your playlists are lost. They're still shown in the sidebar, but they're empty. This doesn't make sense, because you can export your playlists to text files and reload them after you replace your library. So they can clearly refer to song metadata. Why does this break simply because the library was refreshed?
And when Apple decided to shoe-horn the management of its handheld Unix computer/phones into a JUKEBOX application, the results were predictable. I'll spare you the rant.
Today, iTunes suffers from even more baffling functional defects. For example, if you subscribe to Apple Music and you find a show you like, there's no way to bookmark or save it so you can listen to it in the future. Also, there's no way to right-click on an episode and say, "Other episodes" or otherwise see them. And, when you reach the end of an episode, it doesn't play the next one; it just repeats the same episode forever (and there's no control for this behavior).
To this day, photo syncing doesn't work. I don't even know how Windows users are supposed to copy pictures off their phones. Millions of people have been E-mailing pictures to themselves for 15 years, and that's pretty sad.
And need we mention the disastrous implementation of Music Match, which had iTunes replacing users' files with bogus versions of songs with the same name from the iTunes Store?
