Add me to the list of people who quit FEH as well. Fully agree with the above being one of my reasons for leaving.
Other reasons include:
Gacha sucks. Sure the rates are not terrible and the pity system is nice, but most of the 5*'s I did get had terrible stat RNG. Which leads to...
Stat RNG is crap. Maybe it's from a viewpoint where I got clearly suboptimal stats on some of my units but man I didn't enjoy looking up variances in stats between all the units.
Summoning more meant I had to manage my inventory more. I like to collect units but man all that inventory management wasn't my idea of fun.
Most of the difficulty ends up being "lose 1 unit and fail" which, while not THAT bad in an actual Fire Emblem game (since it's a restriction/choice you make), ends up being unfun here.
Orbs are supposedly generous, but I lost interest in grinding all those missions. They do have a nice interface for jumping between the missions and the quests though.
The rhythm game is dumb.
The only real positive for me is that the game is funding actual Fire Emblem game development probably so I'm hoping FE Switch ends up being good.
Oh yeah. Natures are another reason I gave up too. Its not fun pulling one of the best units to find that they are actually one of the worst because they got shafted with Negative Speed.