I get this question a lot. "Why does Apple make its own Apps and why are they not as good as the third party Apps?" Let me try to answer this here to the best of my ability.
Apple makes Apps on its own and offers them for free (at least most of them) with its operating systems, like the iTunes App for Mac, the Photos and Keynote, Numbers and Pages App for the iPhone (and the Mac too). The idea behind these Apps is for Apple to sell a completely workable computer/iOS device to its customer. In the Windows days, you buy a computer and then you have to shell out more money for different pieces of software that you needed for your purposes, like Microsoft Office or Adobe Illustrator or Photoshop. Of course there were cheaper or free versions of these made by third party developers, but most of times, there were very few alternatives, that were less expensive and reliable. But in the Apple ecosystem, as far as I remember, software (now everything is called an App) was never the money making unit on its own. Software was used as just another tool to make the experience of using an Apple product better. That is the reason why Apple computers in the past always shipped with a productivity suite of sorts, like the iLife suite, that consisted of Apps like iMovie, iPhoto, iDVD, etc. While Windows computers had some of these Apps later, built in (i.e., built by Microsoft), they were not as good or as useful as their Mac counterparts. In fact these Apple built software programs were one of the major attractions for customers looking to buy a computer, mainly for personal use, as Apps like iPhoto made everything from managing family pictures to making gorgeous photo books, a piece of cake.
At that time, Apple of course also made Apps like iWork suite that it was selling for a price (like it still does with its 'Pro' Apps now). This was mainly because, the Mac was not too popular with the Business market and people seldom used their personal computers to manage spreadsheets! However as the Macs started becoming more popular and the culture of bring your own PC to work became more prevalent, the demand for productivity suites for Macs also increased. Though Microsoft's Office suite had always existed on the Macs (well at least after Steve Jobs made that deal with Bill Gates in the late nineties), Office for Mac lacked the elegance of Apps made specifically for the Mac, rather than Apps ported from their Windows counterpart. Then Apple developed its own productivity suite called the iWork, that included a set of stylish, workable, 'Apple like' Apps, that were though not as feature packed as the Office for Mac Apps, were ideal for most of the customers. Even these Apps were made free for both the Mac and iOS recently, as Apple has started using Software (including the OS itself) as just another thing that adds more appeal to its products or the software helps the hardware sell, not the other way around.
These Apps made by Apple are made with one simple goal in mind. The iPhoto App came preinstalled with every Mac, so that anyone who buys a Mac, can download their pictures right away on their new computer and start working on it, without requiring to purchase additional Apps or download Apps from some unknown website. So anyone who buys an Apple product will be able to get all the basic things done, like mild photo or video editing, manage documents, spreadsheets and presentations, etc., right out of the box. These Apps are again not the best Apps out there, but are convenient and perfectly usable for most of the customers' needs. But say someone needs a more power packed photo editing App, for example, then there are a lot of options to purchase or download other Apps from third party developers, like Adobe's Photoshop for example.
So as a customer one can be rest assured that though all your needs might not be satisfied by the Apps built by Apple (that are mostly free, nowadays) to the fullest, most of your tasks can accomplished on your Apple devices using the Apple Apps, most of the times. They are not built for you, but are built with keeping in mind the collective need of the average customer. For example the Podcast App that Apple has for the iOS devices, received some attention with iOS 7 introduction last year. It became a little more efficient and a little less buggier. I have been using Downcast as my Podcast manager for a while now and it works generally fine, except for occasional crashes and not so intuitive interface. But when the Apple Podcast App was re-hauled I thought I will give it another try as I was getting bored of Downcast. I had used the Podcast App when it came out a few years back and it was a total mess. It lacked basic features, clarity and worse it was very unstable, so I deleted it right away.
So how was my experience this time around with Apple's Podcast App. It wasn't good. That does not mean that the App was not good. The App looked and worked much better than before. But it was too simple for me. I could not find my most often used features with Downcast in the Podcast App. For example, I still cannot figure out how to mark a list of podcast episodes as "Read", a task that I use so much on a regular basis with Downcast. Also I cannot swipe left or right when a podcast is playing to advance the track (say for example to run over an advertisement), that I can do with my Downcast App. This is important when you are driving and you want to scrub forward without seeing your iPhone screen. But just because this App did not suit my needs, it doesn't mean that Apple Apps suck. I have many friends, for whom the Podcast App is more than enough and perfectly usable and the best thing is that it is free, unlike Downcast. On the other hand, I hardly edit photos, and even more rarely do I edit them on my iOS devices, so I don't have any other Apps for managing or editing photos on my iOS device. The Photos App by Apple is more than enough for my needs. Whereas some of the people I know have tens of Apps for editing and managing photos, some them as expensive as $10 each. So the moral of the story is that if you are a power user or your specific needs are too niche, then the probability is that you won't find the Apps made by Apple that came along with your Apple device, to be sufficient for you and you might have to look elsewhere (App store) for your power App. However for an average Joe (I might be an average user in one area while a power user in another), Apple's Apps make sure that the device you purchased work out of the box, readily, with no contingencies attached.