Guild Wars 2

Why am I forced to waypoint out of instances (charges me silver too), instead of just walking out the way I came in. A bug? or is it meant to be like this?

Also, on some, I can leave without using waypoint.

Assume you enter an instance through a closed door. You stand before that door and turn around to leave – nothing happens. You walk away a bit, turn around and walk towards the door – you get the choice to leave.

It’s simple: There is an area that needs to be entered in order to trigger the dialog window for leaving. If you simply stand there, you haven’t technically entered that area, so you need to leave it first. Move around a bit, then try again.
“Weve got to get in to get out” holds no sway here

No that is not correct, this is definitely a bug now.
I’m doing mapping of all the cities on my norn character and I get the entry dialogue to enter an instanced area in any major city but once inside will not get any exit dialogue and have to exit to character select to get out or use a waypoint.

You should probably single out these instances you claim to be buggy. I’ve explored most of the world on my main (also a norn, though that isn’t probably not a deciding factor), including all the cities, and at least I haven’t personally come across any instance with no natural way out.

There were some instances in Divinity’s Reach where this has happened. They forgot to add an exit point.

It’s not that they forgot to add them it’s that they have suddenly disappeared. They WERE there before.