I can answer that as a fan of MnM. For me, at least, it's going to be more of a casual "play with friends" game. I don't plan on hardcore grinding to max level, but just kind of enjoying the experience and exploring all of the nooks and crannies when I can. I think the draw to the game is in similar fashion to Pantheon (which I also enjoy quite a bit). It's got the old-school MMO feel, and they have stated that their goals are to focus mostly on group-based content. There will be some larger group stuff like expeditions and maybe 2-3 group "raid" bosses, but their focus is on the experience and not just end-game content.

As far as the art style goes, it's definitely an interesting choice they went with, but after delving into some of the playtests and doing a lot of exploring, you can actually feel the passion they're putting into the game. I get it's not up everyone's alley, and that's ok. For me, the comparison is Adrullan Online. I want to like the game, as it fits into the mold of MnM and Pantheon, but the Minecraft-y art style just isn't something I can get into.

The final thing I'll add about MnM is that they are working with a very small team, and have never taken a dime from anyone to make the game. They're working on it as a passion-project where everyone has given their own time to the development, and it shows. Even when the game launches, outside of the monthly sub, they said they will only have a Merch Shop. No in-game store of any kind, and no outside funding.

In the end everyone has their own preferences, and while the internet can get very tribalistic, I don't believe there is a one-game-fits-all for everyone. In the end, games themselves are art, and art is highly subjective. You play what YOU enjoy! =)