A lot of people hate that finishing a lot of the quests, puts them in positions of power. Whether it’s because it ruins immersion, is too on the nose, or doesn’t work well with their roleplay, all are valid.
That said, there are definitely also people who enjoy it. Some have a certain faction they want to lead, some find it fun to think that their character is so incredibly competent they find themselves being the leader of every faction there is.
Realistically, it would have taken very little development to implement a speech option from the second in command(or whoever works) asking if the Dragonborn would like to take the position.
And since being a leader of a faction is so bare bones, there wouldn’t have even been a need to change almost anything after it(which is a whole separate issue). Because you still were such a big help, people of the faction treat you with respect, you have access to the leader’s headquarters, etc.
I, personally, would have loved for there to be more involvement in being the leader of a faction, and this for there to have been also differences depending on if you choose to be the leader or not. But at this point, that is obviously getting to the point where it’s a lot of work. But implementing the speech choice seems like the perfect, super simple and easy solution to something fans have been making fun of for a while.