Um, Ah

It’s considered bad form to pepper a speech with um’s and ah’s. Then, where did the recent annoying practice of sprinkling these noises into written essays and articles come from?
I’m especially fascinated by the fact that male writers seem to be using this device, even though it reads more like baby talk than sophisticated repartee.
Consider this excerpt from a piece about the Tony awards by Time’s James Poniewozik:
Don’t get me wrong: I enjoy a good August: Osage County joke as good as the next guy who’s, um never seen the play
Given, Mr. Poniewozik is not writing about manly stuff like war or sports, but I still find this unseemly.