Let's discuss how truly silly a "subtle spell" fear spell would be. Fear causes creatures to "take the Dash action and move away from you". So they MUST know you cast the spell for it to be of use. It's useless.
Now let's discuss what a "game changer" a Careful Fear spell would be. Fear spell is roughly as good as the Slow spell, which doesn't suffer from issues with targeting allies. Nor are cones all that hard to line up to avoid your allies. I've never heard someone claim the Fear spell would be a "game changer" if it didn't impact allies.
Now let's discuss how truly silly a "subtle spell" hypnotic pattern would be. It creates a flash of a pattern up to ONE HUNDRED AND TWENTY FEET AWAY FROM YOU that "appears for a moment and vanishes". So it already rarely mattered if they knew who cast the spell, and if it did matter you could already try and cast from behind cover and hide because your targets rare saw your tiny hand movement or heard your verbal components. Even in close quarters, it's not like you're wearing armor and it will be hard to figure out who cast that flashy light thing!
So how about Careful spell on hypnotic pattern? Again, I've never heard people complain it causes too much friendly fire. It's not a radius as big as a fireball after all. Not too hard to line it up right.
These are not game changers. They are situational benefits which are nice but not that meaningful to most games.
