That'd divide the grass roots crowd. At Primary School I played "goal hanger" so certainly would agree with you. In my older years I was a pub centre back and I'd much rather have stepped up two yards to win a free kick than chased after a pacy youngster who already had a two yard headstart...
Agree with the OP, blatent offside should be flagged immediately for the reasons HKFC states. You could actually see teams scoring from set pieces that shouldn't have been or goals being reviewed across multiple phases or offside reviews for corner decisions if it's taken to its logical extreme...