Some have mentioned obstacle clearance, but I'd guess it is that way
to take you across the extended centerline of the runway
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

The preferred alignment is for the VOR radial to cross the extending
runway centerline 3,000 feet prior to the landing threshold.

Here (3BS) they picked a radial off KMBS that crosses the center of
the airport making all runways a circle-to-land. OTOH we don't have
any runways that come close to lining up with KMBS.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com