How would you feel, if they took the niche series Metroid. Took away all of the exploration aspects of discovery to make it easier for new players. Along with simpler controls, a more cinematic story that retcons a lot of prior games, and simpler level design that makes the game easy?
Oh yeah, they did that with Metroid Other M.
The same thing happened with Awakening really, except Awakening caught on. I really like Awakening, but dude. They took away all of the challenge, tenseness, and amazing story that Fire Emblem used to have. Really, I am glad they have made a distinction with that, and made Conquest. People have been loving Conquest according to reviewers, because it provides a way deeper experience than Birthright. But those that are new to the series still have what they like as well. It is literally a win-win situation.
The difference is that the Metroid formula worked back then, and it even worked with Prime. The Fire Emblem formula didn't, the series was all but dead when Awakening came out, it was even supposed to be the last game because it wasn't good enough to continue.
So with Metroid, you have a popular, successful franchise, and you changed it. That's a bad idea.
With Fire Emblem, you have a unpopular(yes, a dedicated few, but still), unsuccessful franchise, and you changed it. That was a good idea.
Gotta stick with what works. It's like in basketball, if Lebron is cold today but JR Smith is knocking down threes like Curry, then you give the ball to JR so he can shoot from the perimeter. The hot hand gets the ball.
Edit: Not to mention you can easily get back the same challenge you got from the original, in Awakening. And the story, while unoriginal, wasn't so bad.