aircraft
If the question is why is it on the airspeed indicator, I can only guess and here it is.
Unless the engine fails at lift off, no runway remaining and your decision is to continue and possibly that would be best done at angle of climb. This is the only instance that I can think of that I would climb at this speed.
At any other time Vyse would be the most aprropriate speed. Even if it is in the cruise and you want minimum descent rate. So as the most appropriate speed in , most cases it would make sense to placard it. Having said that Vyse changes with weight so the placarded speed is not always correct either.
My logic anyway