You can call it childish if you want, but a lot of people are unhappy with the economy in general and rising costs in particular. Energy costs are a big part of those rising costs and, like it or not, the AI vendors and their data center projects are an easy target.
I don't think it's necessarily a "backlash" to all the hype but the hype certainly made them a target
Mandating renewables for data centers would have left you with checks notes a shitload of renewables after the AI bubble bursts.
Something that should (with good governance) lower energy costs.