The reason is that whereas male announcers making a commercial such as this sound forceful and excited just as the "copy" calls for, female announcers with their usually higher-pitched voices, often sound, well, "hysterical."
I think that the same kind of gender differences are what makes Hillary sound so unpleasant when she engages in "forceful oratory."
YOu may have something there.
When Hillary said
"I'm sick and tired of ..." (forget what she was sick and tired of, maybe Bush fighting the war on terror) ...
SHE COMES ACROSS AS SOMEONE'S MOTHER-IN-LAW. A Nag.
When Gore says:
"He played upon our fears" ... in his best hyperventilated rage ...
HE COMES ACROSS AS A MANACING PREACHER.
I know what you mean, but no one, repeat, NO ONE, was better with forceful oratory than Margaret Thatcher.
And she NEVER had to raise her voice to make her point.