Plasma storms are not a waste for SB as it prevents its destruction by bombers, one of the number 1 killers of starbases today, especially Orkulus.
He meant that SC upgrades for SBs are pointless in Plasma storms.
Also Asteroid Fields and belts make all ships miss a certain (or higher?) percentage of the time. Not sure at the moment of the exact value.
I think that in Asteroid Fields, weapons hit 20% of the time. I'm not completely sure though.