I think you do have to consider the user expectations here. If C3 says "we have flowcharts", but lacks a lot of functionality in most other flowchart software, it seems more than fair to be disappointed.
And without a feature roadmap or similar communication, users have no idea what's still to come, what's set in stone, what's open for feedback, etc. We don't know what skill level or depth is planned, so we don't know how to judge its competency. Eventually, the feature gets so far down a road that popular/necessary additions can't be added (the code is too complex, there are too many tutorials in the old way, etc).
I wouldn't call this entitled. To me, it's a expected reaction of the system in place, where features are unable to stay in beta longer than a release cycle.
For example, if Flowcharts were called "Flowcharts (beta)", user expectations would be in line with the developer intention - namely, that there's work to be done. This would remain "Flowcharts (beta)" until the vision was more or less achieved. Part 2 would be updating the Flowcharts thread whenever new feedback was sought by development.