I can think of several reasons not to do this and absolutely none to support doing so.
It is illegal in all states to drive with only your parking light on and even if your parking lamps are wired as DRLs, they are still parking lights.
DRLs have specific standards and are never combined with turn signals. Having the parking lights on makes it much more difficult to tell if the turn signals are on, both day and night. This could be overcome by having the parking lamp turn off whenever a turn was indicated, but seems like a lot of work for little gain.
