The ACC did have some decent teams pre-Florida State, but did not have the cache to get a major bowl tied at that point. Before Florida State, the best bowls the ACC seemed to regularly be in (not every year, but often) were the Citrus (bigger then than it is now) and the Peach (bigger now than it was then).

That is not to say the ACC wasn't a major conference, but it was in an environment with a lot more major conferences and would have been much further down the totem poll.

Today, it still has issues, but I think it's long term strength is usually looked at as less than it should be. I'm not an ACC fan, but I think a strong argument is there that it's long term success should now be ranked as more likely than either the PAC-12 or Big 12.