This widget originates at the time of Mendix 2.5 and is a wrapper on top of the TinyMCE library. Additionaly, a lot of custom functionality has been built into this widget very close, or even into the library. For the past years we did our best to keep this widget functioning in all the versions which have been released since, but have come to a point to decide whether the investment to totally rebuild this widget outweighs the use of alternatives.
So, a combination of:
made us decide to not proactively support this widget as alternatives like CKEditor and BootStrap RTE are already available. These widgets are also easier to maintain for us as they stay close to the library because they don't have customization implemented. We also strive for a sensible footprint as we simply can't support an infinite number of items.
Ronald, can you please tell us why you don't like the current alternatives? We appreciate your feedback.