Sing it out loud the way you would like to hear it and try to play it that way.

Usually they write it that way because they want 3 beats to be sustained with no emphasis on the new half note. They do this instead of putting a dot on the half note. If you have two up bows, or two down bows on a quarter and half note with the same note you would stop slightly and continue in the same direction to hear the new note.