I think the tower was a bit harsh then because at several large airports ALL
aircraft are asked to keep the transponder on during ground operation all the
way to/from the gate. TCAS systems have a mode which gets rid of most unwanted
warnings for takeoffs and landings. There is nothing at all wrong with turning
the transponder on when approaching #1 for takeoff, it's better than forgetting
to turn it on at all. If it is an ongoing problem at that airport try calling
the folks in the tower to find out why and how they would like transponders
handled on their field.