No, we didn't, mostly because ISPs didn't have the technical capability or demonstrate the intent to violate net neutrality. We didn't need rules to stop people from doing something they were simply incapable of doing.
Once they got that ability, and showed signs they would use it, we needed the rules.
The better question here is why are ISPs lobbying so hard for the right to do something they are also promising they would never do? Companies don't fight to overturn regulations they have no interest in violating. Or, at the least, if they do they tend to make a better argument for why that's happening.