PoB-grinding is completely optional if repair rates are nerfed like this. Sure it is more effective, you wouldn't progress in your siege with less frequent or shorter attacks near as much as through grinding, but you still would, with fewer ships required than before. It seems that's something many in this thread either forgot, ignored, or just didn't understand.
And you seem to have forgotten, ignored, or just didn't understand that there was a race to destroy the other base so you could keep your own.
Which was more of a feature of this event specifically, not of the new PoB balance. Perhaps it hasn't been clarified yet, but this rebalance direction wasn't planned for siege races, PvP Death Penalty reduction to 30 minutes, or anything specific to this event. It was meant to improve the mechanics of any regular siege.