This debate has been going since the days of AOL and CompuServe. As here, it usually misses the differences between public content, private content, and corporately farmed content.
Twitter etc are corporately farmed content, and they all provide web and app access. The access method is just a front end.
Personal content in apps isn't usually all that interesting. It's hard to think why anyone would care about my Angry Birds scores, or what level I'm on in Candy Crush. (If I played Candy Crush, which I don't.)
If you want to make an app that shares content on the web, it's not difficult. I don't see a problem with the fact that it's extra effort, and if you're going to do it you need to justify that effort in some way.
Twitter etc are corporately farmed content, and they all provide web and app access. The access method is just a front end.
Personal content in apps isn't usually all that interesting. It's hard to think why anyone would care about my Angry Birds scores, or what level I'm on in Candy Crush. (If I played Candy Crush, which I don't.)
If you want to make an app that shares content on the web, it's not difficult. I don't see a problem with the fact that it's extra effort, and if you're going to do it you need to justify that effort in some way.