Why do outsiders get at-will teleports?

[Senko]

The Rot Grub wrote:

Granted, demons aren't that well organized or cooperative, but what's to stop creatures with teleportation abilities from teleporting away when they're weakened by the PCs, grabbing their friends, and coming back with far greater numbers?

Teleport Tactician.

Dimensional Lock.
Planar Boundaries.
Track Teleport.

There's a lot of reasons why trying to teleport away can be a bad idea especailly if your initial attempt to ambush them failed. Same with scry and fry if you scry someone who can sense and backtrace you your hidden sanctum may suddenly get a visit from an imp to test its defenses followed by a full assault sqaud if you don't have defense up to stop the imps arrival and departure.

[David Neilson]

I am oddly imagining an caster making a specialty spell that only alerts when an imp shows up, or has a sorting process. Tiny goes somewhere seemingly nice and attackable, small or larger gets Dimension Locked room with a Holy Smiting trap.