Skeumorphism isn't inherently bad. But problems commonly follow when designers aspire for authenticity over sanity, which leads to bad user experiences. Apple's Contacts and Calendar apps are cumbersome to use because they try too much to replicate real world objects.
More alarmingly, it limits our creative thinking. When the iPhone was first presented in 2007, Jobs kept on reminding us that these user experiences were only possible because of touch screens. We were no longer limited by static physical keyboards. The iPhone doesn't even have a shutter button in Camera.app! There are countless other examples of digitally authentic user experiences which are only possible if we think outside the box and beyond real world objects.
More alarmingly, it limits our creative thinking. When the iPhone was first presented in 2007, Jobs kept on reminding us that these user experiences were only possible because of touch screens. We were no longer limited by static physical keyboards. The iPhone doesn't even have a shutter button in Camera.app! There are countless other examples of digitally authentic user experiences which are only possible if we think outside the box and beyond real world objects.