Okay so after a few playthroughs of TMB, I'll say I enjoy it. I have 2 major complaints:
1. There is a lack of narrative sometimes and if you're not with fun people it feels mechanical.
2. It just makes me want to play D&D.
#2 is the same complaint I have with Gloomhaven. Also HP management in Gloomhaven as well as initiative is such a chore that I use an app on my tablet, which streamlines it, but then once again makes me ask, why am I simply not playing D&D? The HP and initiative in TMB is great.
I kind of agree with you on your first point. Each encounter card is kind of a choose-your-own-adventure where you either selection option A or B, but since the cards are randomized, the story element takes a hit because their is no cohesion or over-arching plot. Also, once you kill the boss there is a "that's it?" kinda moment because their is no campaign or legacy component (which I understand gets fixed somewhat with the Age of Tyranny add-on....can't wait to get it).
Your second point, however, I don't feel the same, because it's two different beasts imo. First off, I have to preface by saying I haven't played D&D in ages, but I did play it for over 20 years in my youth. I only recently have gotten back into board games and I have to say one of the most enjoyable things about board gaming is that it's more accessible for the general public, and also it allows for true cooperative play for everyone. In D&D, you need someone to DM, and the quality of any campaign boils down to how good your DM is. D&D definitely has more depth and more creativity, but it's also kind of a 1 vs many mentality, which is why I never bought Descent (the board game) because I don't want to play against my family and friends anymore, I want to be on the same team (I used to DM a lot).
Which is why I love, love, love Gloomhaven. Because now I get to adventure with all my friends and family, and the "DM" is automated. Sure, it's not as creative or fancy as a human DM would be, but it is sophisticated enough to allow me to enjoy the game immensely. It's also why I love computer RPGs, because I get to just play the game while all the rules and background stuff is automated for me. However, for me computer RPGs are a solitary affair (Fallout, Skyrim, etc), while board games is something I really enjoy with other people because it's so much more social.
Same with Too Many Bones. The game isn't ground-breaking as far as combat, character advancement etc.....but it's such a joy to play because of the components. And this goes to board games in general. Something about sliding pieces around a board, holding cards in your hand like poker....it's the physical elements of board games that's got me hooked in a big way. Maybe D&D is more like that now? When I played D&D is was hand-written character sheets, DM hiding behind a screen, and moving lead figurines on pencil-drawn maps lol.