Why are non precision approaches not lined up?

Stan Gosnell wrote:

pl

The term 'precision approach' refers to having vertical guidance (a
glideslope), not to the runway alignment. A precision approach does
have to be aligned relatively closely, but not precisely. I can't
recall the exact number of degrees off the top of my head, but it's not
exact.

3 degrees

Dave Butler wrote:

Stan Gosnell wrote:
A precision approach does
have to be aligned relatively closely, but not precisely. I can't
recall the exact number of degrees off the top of my head, but it's not
exact.

Here's an example of a precision approach that's not aligned with the runway,
the LDA Rwy 6 at ROA, Roanoke, VA. Terrain appears to be the motivation for the
misalignment.

http://www.myairplane.com/databases/.../00349LDA6.PDF

That is not really a precision approach so far as most of the world is concerned.
It is a FAA category of IAP that does not meet the ICAO definition of a precision
approach. The FAA calls these an approach with vertical guidance ("APV") and they
provide the definition in the AIM:

"b) Approach with Vertical Guidance (APV). An instrument approach based on a
navigation system that is not required to meet the precision approach standards of
ICAO Annex 10 but provides course and glidepath deviation information. For example,
Baro-VNAV, LDA with glidepath, LNAV/VNAV and LPV are APV approaches."