Different aspects of Tapas have varying responsibly. Tapas, for example, is 100% responsible for server maintenance and keeping CPMs up for ad revenue. Creators are 100% responsible for generating quality content in a consistent manner.
Tipping is something that falls to both parties. Staff and creators need to both keep readers aware of the function. As far as for creators, they need to do something else beyond "just goodwill" to entice readers to tip. For example, if you are planning on a physical printing (e.g. $15) and individual readers tip that much, by all means, send them a copy once the print run is done. Other creators have had other ideas in the past beyond just this. It would be great if Tapas built a list of creators who are offering something extra for tippers and promote that. Right now the tipping tile on the app has been essentially the same for the last six months. It could use an update.
Maybe staff and creators can also work together to create a "culture of tipping" where its pretty much the norm to tip series that you are reading. 25 coins per page or 6 panels works out to $4 for a 200 page graphic novel, which is less than a cup of coffee.Tipping could go a very long ways to helping creators create if every single subscriber chipped in something. Maybe Tapas could create an automated pop up after 50 views of any series they are reminded to tip and there's already a 25 coin button waiting for them to tap.