First off, I'm not taking a side on the matter until I actually know what was decided. We all knew this was coming, whether it's good for the public interest or not. It's ridiculous to worry about the specifics until we actually know what they are.
That said, "rules [...] that were written in the era of the steam locomotive and the telegraph" aren't inherently irrelevant to modern society. I'm pretty sure that that Constitution of ours is still pretty relevant despite being written before that era.
All that aside, I will grant that it's worrying that five people decided the fate of the Internet in the United States. Don't assume that the dissenting voices were entirely unheard. What really scares me is the idea that they may have taken a gamble by influencing language they thought was terrible, ceding the battle to win the war.