Shadows is definitely not a feel bad mechanic. Sure, it’s powerful, particularly in solo, but it’s such a theme win, I can’t help but think it’s cool when it happens, even if it essentially is screwing me out of a win.
Its ludicrous to call this a design fail in my eyes - the difficulty is pitched mostly where they wanted it. A couple of scenarios have a small issue because they don’t put enough of a clock on you threatwise, but generally they’re designed so that players not familiar with card games can play and win more than they lose. Expert mode increases that difficulty to the point that I don’t always win solo, which I think is generally fine.
They’ve listened to feedback from the player base, and I think it’s fair to say it’s varied - experienced card game players have generally decided that the game is easy by comparison to previous LCG’s, while new players attracted to a card game for the first time find it hard. There are multiple ways to adjust the difficulty of this game, either yourself or tools the designers can be used, but they’ve provided a couple of simple variants for the moment that can make the game easier or harder, leaving the option for further future development if they want. It’s not intended as a magical cure all for difficulty, but it’s easy for them to put out and for players to implement. They didn’t need to put out anything. It’s entirely optional. More optional stuff is better than less optional stuff...