Time Capsule is meant to be a backup. Sadly, that's it. The idea is *not* to use the drive for other purposes, which would wear it down. The argument, as I understand it (not necessarily agree with), is that doing more would weaken the backup.
There are other devices that can provide Time Machine backups and network shares, like Synology. Some of decently priced models can also use a RAID 1 (two mirrored disks with redundant data). That makes it more "fault tolerant" (which should never be thought of as a backup). I mention this to highlight the difference between a device meant to share and backup data.
You can set up shares from your computer, which you probably already knew.
All in all, I find a lot of Apple devices to be "limited" in ways that might be more aptly described as "focused" instead.
That said, I could be wrong. I looked into if these could be used as network shares and my research said thay they could not. I was hoping to see what a new model could offer, but that doesn't seem to be happening. :/