Good points, but to add to the sources of instability ... a first time user of a piece of software may be very appreciative of its simplicity and "intuitiveness". However, if it is a tool that they spend a lot of time with and is connected to a potentially complex workflow, it won't be long before even they are asking for "this little extra thing".
It is hard to overestimate the difference between creating tools for people who use the tools for hours every day and creating tools for people who use tools once a week or less.
It is hard to overestimate the difference between creating tools for people who use the tools for hours every day and creating tools for people who use tools once a week or less.