Sales of the Bronco had been declining since 1990. The market for a full size, two door SUV was dwindling in the face of Ford's new sales juggernaut at the time, the Explorer. The Explorer was more practical, more family friendly, and more economical. GM also discontinued their 2-door SUVs in the early to mid 90s (Blazer, etc). Ford released the Expedition in 1996, the year the Bronco was discontinued, and its 4-door, three row seating proved more attractive and popular to full-sized buyers than the outgoing Bronco.

There was actually a sales bump for the Bronco in 1994, often attributed to the publicity from OJ's chase, but it was short-lived.

http://www.usatoday.com/story/news/nation-now/2014/06/17/the-bronco-brand-after-oj/10257945/