Because if you want to sell an AI product you now need to hire an army of lawyers to do the state-by-state compliance. This dramatically increases the costs and slows down critical innovation. Another common argument is that any regulation will allow China to 'win the AI race' but I don't entirely agree with that premise - it's not a 'race' and if China 'wins' it'll be because they largely use their debt to finance effective high ROI industrial policy rather than mega tax breaks.