Should've listened to So Many Insane Plays, they spent like 45 minutes on this in their set review, heh.
I mean, that's not really that different from mana in the modern era, which is also a resource you accumulate and which usually opponents can't take you back off of. The thing that makes energy feel uninteractive in Kaladesh isn't really that it's a resource you can't directly target, it's a combination of the energy sources adding it in significant quantities right upfront and a lot of the sinks letting you spend it in large quantities quickly. Something like Aether Hub is easy to keep fair even in an energy-rich environment, and in general the stuff that has other restrictions on expenditure (like attack triggers, or additional tap and/or mana costs on top of the energy) are fine unless the effects themselves are innately absurd like Marvel's. Note that the energy decks are heavily defined by creatures that are infinite sinks for turning energy into stats -- Longtusk Cub, Bristling Hydra, and Electrostatic Pummeler all make giant stocks of energy explosive in a way that Aetherstorm Roc or Glint-Sleeve Siphoner don't.
