It's not that the state of the internet pre-2015 was a disaster but, prior to the 2015 reclassification, we were already starting to see abuses of net neutrality. When ISP's and telecoms started to block VoIP traffic because it cut into their phone services, it was unprecedented because no one had really prioritized data based on the content up until that point. Once that started happening and more companies caught on to it, it became a point of contention. While the 2015 reclassification wasn't a perfect solution, it did encapsulate the gist of the argument by saying that, like phone calls, we can't prioritize data based on content.