Well, that is a weird example. I am looking at things like the Two Weapon Fighting fighting style and the Dual Wielder feat. They are thematically similar but designed so that they interact. They stack, essentially, because they don't improve your ability to fight with two weapons in exactly the same way.
The reason the Fancy Footwork trait and the Minotaur traits are not like the Ritual Caster feat is that they are not self-contained. What I mean is, if you have a Swashbuckling Rogue, he can't get the +10 ft. movement bonus and the ability to ignore difficult terrain without wasting 1/3 of a feat. Which means those options, for him, are essentially removed. It is a little sloppy, that is all I am saying.
Ritual Caster isn't like that, there isn't any part of that feat that the Warlock is missing out on, so it doesn't hurt him in any way.