Yes and no. 1 1/4 came into play circa 89 dubbed by Fisher as "Evolution" headsets. Bigger headtube = more strength. More balls in a headset bearing = longer life.
Many reasons, but one of the biggest reasons for its widespread use was the interest in suspension forks. Stronger headtube = more focus on making better [lighter] suspension forks.
There was a lengthy discussion on the VATB list about this a week ago.
I think I recall them being popular throughout the nineties. Although I never owned a bike with one. :roll: