I think you didn't get the joke.
Idea behind the joke is that those apps were not needed at all in the first place, it is only that person from the joke had grand idea lurking in their head that those will be super useful. If those apps would be needed a person would take time to build them. Now building useless apps costs much less.
Better UI doesn't matter if something is purely a "wannabe application" in someones head.
Ergo, if you don't have time to build out some idea - that is a clear indication such idea is not good or not so useful - even if you still have an urge to build it, subconsciously you already know.