If there was a single feat that "shored up" your weak saves, you're right - everyone would take that instead.
Calling it a trap option because adventures doesn't feature enough challenge is entirely backwards to me. If the adventures doesn't challenge players, that's a huge bug and certainly not a feature. Let's not start treating the edition's carebearian nature as a good thing.
Sure there can be campaigns with doesn't feature combat heavily, and there the feat might be less useful. But in published adventures there are a lot of monsters to be killed, and saying "you don't need to be particularly good at killing to succeed" is the ultimate resignation to me.
What game would D&D be if you could kill its monsters on autopilot? Why would you even waste your time dungeonbashing if there isn't even the illusion of challenge and possible defeat?!
No - a 40% damage increase is and needs to be a huge deal. In fact, my entire argument is that it is too huge a deal, and that the game would be much better off if it was reined in. Both in combat-heavy campaigns and obviously also in your social/exploratory campaigns. In campaigns where it sees a lot of use, and in campaigns where it is never taken. In all campaigns, in other words.
Most of Quantum Physics feels backwards to me, but that doesn't mean that it's not right.
If you as a player don't need to take GWM or SS to successfully complete combat challenges, and you take it anyway, you are wasting a ASI.
Even in a campaign where the ONLY meaningful challenge is in combat, if you are ignoring your vulnerability to your non proficient saving throws, sooner or later you are going to get locked down and killed.
The edition is balanced out of the box for the casual player. It expects advanced players to have an advanced DM who can tweak appropriately. It is essentially Uncharted, not Dark Souls. Guess which of those games sells more copies, even as the other is revered by gamers as the perfect answer to the carebearian challenge of most modern games?
And the game I play in with the Barbarian is combat heavy. It's also Social and Exploration Heavy. For combat, we routinely hit our level appropriate Daily XP budget over the course of 2-8 encounters (yet almost always 18-24 total rounds) But because we don't go gonzo on our character sheets, the DM has the ease of being able to design these by the book, rather than her having to tweak everything. And she can challenge us in the Social and Exploration pillar because we haven't nerfed ourselves there.
Now, what I wouldn't mind would be WotC to provide an official tweak for those good players who want to up the challenge. I'm going to be testing out with TftYP a couple of difficulty settings for my players to choose from before each chapter when they build their characters.
Hard - Starting Array of 13, 12, 11, 10, 8, 8
Legacy - Roll 3d6 in order
Legendary - Starting Array of 11, 10, 9, 8, 8, 6
That's an interesting spin on It! CapnZapp & his crew seem to be caught in it, and thus find the game 'too soft.'
I am absolutely convinced that WotC put these kind of traps into this edition because they learned that the only way to win the power gamer war is not to play. This edition emphasizes real choice in character design. If you want to be an overpowered combat monster, you can. Most importantly, you can take whatever you want without fear that you are going to nerf yourself out of relevancy in any pillar, provided you use the standard array or point buy to start with and put your highest stat in your combat ability (as per the directions of the game).