The justification for building the Southwest Corridor so far from Pembina Highway has been that it will create opportunities for higher density development. Currently, Pembina Highway already has significant multi-tenant commercial and higher density housing that is very accessible to bus stops. Transit service along Pembina is exceptional precisely because bus traffic between the University of Manitoba and downtown is very high frequency. Reducing this service in order to move transit to areas which currently have almost no amenities will dramatically impact the usefulness of public transit in Winnipeg.
Here is a map of the existing medium and high density commercial and residential units on Pembina Highway, compared to the dogleg route, showing what bus riders will be losing high frequency service to: