I don't know how the HGSS pricing broke down, but in terms of "set completion" theme decks were never a good way of going about it. The main thing I'm quizzing here is this pretense of Battle Decks as some unscrupulous cash grab where Theme Decks were somehow manna from heaven and along those lines I want to ask – if all you're after are the exclusive non-holos/ice shard holos, aren't you being cajoled into buying a whole deck you might not want, just for 1-2 cards?
These new decks are doing something similar, but it's why I see this as an apples-to-apples, and I don't really see what's been lost here. In both cases they're lousy – whereas Japanese decks used it as an opportunity to spread unique cards out of their respective main sets and help reduce the size of main set, EN theme decks only ever offered variants at best. What exactly are we waxing nostalgic for, here?