Das yochid you say there is a potential tznius issue here. I know the fathers quite well. None of them are the type of people that you are insinuating.
I’m not insinuating anything about anyone; I wouldn’t want to go to a girls’ graduation myself (although I agree with Health that under certain circumstances it might be necessary).
And my main point was that your argument, that it’s okay for men to attend because it’s not untznius for a father to see his daughter’s graduation, is fallacious.