It seams many people don't understand HTTP Strict Transport Security.
If I look in SSL Server Test > Recent Best-Rated many Server have to short max-age setting (less than 10 minutes).
And even that is coloured green. I think that is the wrong sign.
With such settings is Strict Transport Security worthless. And I think it is worse, if you think you have a function. But it is configured in a way that it isn't working at all.
I think it should be read if it is below one month. Black if it is below 6 month and only green if it is above that.