I do like OJ's; it's one of a dwindling number of certified Greenville classics. I would hate to see it go. I'm inclined to agree with Dino's assessment that a road diet and/or construction of same would hurt OJ's business. He has skin in the game and he would know. By the way, this can be true even if the planned changes are a net positive for area businesses overall (which I also believe).
However the city's goal is to make the area safer and more accessible by foot and bicycle, with the broader goal of knitting the South Main area with West Greenville. Whether or not you agree with these goals, they've been in process for many years with plenty of opportunity for public input. A cash grab by a private developer would be one thing, but this is a public infrastructure project advanced by elected officials and prefigured by years of public deliberation. The specific impact on a meat-and-three diner, however venerable, is not the determining factor here and nor should it be. Businesses on Pendleton Street will adapt or move.