As pawelp said, it will be nerfed, just not yet. For the time being people will keep spending diamonds to get more HoF's, once the event is over and no more money can be made then they will nerf them, it's the inno way, always has been.
As for it being under review, we do still have a beta server, we did have this event and this ridiculous building there for a month before it was released here, we did complain there, we did say no, we did point out the problems, but yet again it makes no difference. Inno does what inno wants so that inno can rip off their customers yet again. Absolute disgrace.
Can somebody tell me why we even have a beta server? all the bugs from there get released hear anyway and then fixed months later, and bad ideas such as this one get pointed out and we just get ignored anyway and it still gets released. Might as well just drop beta server completely. Other than the fact you get free diamonds over there on the odd occasion it's pointless. Much like how pointless all the time and effort spent on GvG is now that the hall of shame has been released. We put in months of time earning our rank and some muppet with his mothers bank card comes and buys his way into a higher rank than us? What a brilliant feature to add into the game "Work for your rank or simply buy it". Well done.