Why does BF development always remove popular features?

Simple, those who create the games don't understand anything that the community really likes and wants, they are people unrelated to what the community is asking... always like that they get it right, then take it out in later versions

They removed the most essential feature of Battlefield: large maps. 

Commander mode is an essential part of Battlefield and I hope it makes a return as it was in Battlefield 2.

They are just trying their best to make the game good for the largest number of players, so I can understand why some decisions might be controversial to the core Battlefield demographic.

Commander mode was so unpopular in BF2 that for most of the rounds no one wanted to be one. Probably because sitting in base and just pressing scan wasn't a good way to have fun. Server owners also enforced this all because Commanders got 2x points.

After BF2142 the feature went away. It came back a bit in BF4 I think but only through mobile. So it was not that popular.

I was an active Battlefield 2 player from its release all the way until around 2008, and in all that time I honestly never once saw a player complain about Commander Mode. During its active years, it was the most sought after and popular role in the game. I remember times when days would pass before I finally got lucky enough to play a single round as the commander. On more competitive or “try-hard” servers, you often had to stay in spawn and focus solely on playing as the commander. However, the vast majority of servers allowed you to run around and be active in combat while still fulfilling the commander role (99%).

Battlefield 4 featured Commander Mode as a dedicated role. You could join a server solely as a commander and play the entire match in that capacity. The commander role was available to be played via mobile, but this was more of an additional feature since the main way to play the role was still via PC.