This feature solves some of the problems (thanks for pointing it out), but not all.
If a child is born to a single mother, that child gets associated (drawn in the tree) as a child of that person only, which is exactly right. However, when that woman later marries, her single-parent child from earlier times gets automatically moved to being drawn as a child of her new husband as well. I have not been able to figure out a way to avoid this so far.
The same happens when a husband dies and his widow later gives birth to a child out of wedlock. Unless I introduce a new person "unknown father" to the tree, I cannot prevent that child from being attributed to the already dead former husband.
How does that help if you know the father of the child of the single mother and want to note that but don't want him to appear as the husband? I mark them as friends or partners but when I print out the reports it lists him as a husband when the parties had never married.