There is a clear distinction between “complexity” and “complication”.
Complexity:
Something that is complex is made up of multiple parts. Typically, each of these parts, when operating individually add up to much less, compared to what they add up to combined. For example: A great actor, a smart plot and a groundbreaking representation (in more ways than one, to many people) can all be done in isolation. However, for many of us, Sherlock was a combination of all three. In this combination, the value of the show rose much higher than it would have if it was just another smart plot with a small time twist to it. This is the complexity we loved! Each episode was laden with great character development played by some of the best actors in the world, while pushing the plot ahead. The Final Problem lacked that complexity because it lacked in two of the three things mentioned here. The episode was simplistic. In isolation, it was alright and everyone would have treated the episode the way one treats a one-off slip. This was meant to be an ending of sorts, with no certainty that a new season will be made. That combined with the cliffhanger of The Lying Detective increased the potential value of the next episode. The easiest thing to do in this case would have been to deliver. So, my question is - why didn’t they?
Complication:
Complication is very different from complexity. When there are multiple logical steps taken to arrive at an answer, or when there are extraneous elements that must be circumvented to approach a solution, the thing becomes complicated. The part may remain the same and the answer may be very simple. However, the value of the answer does not change based on how you approach to answer the question. Typically, a convoluted plot just complicates a story rather than adding to the complexity of it. The Final Problem was complicated, rather than complex. All that talk about feeding people warm paste - what we were fed was.... well.... a different flavoured warm paste, I guess. The nutritional value of both being the same, no added value there.
So, my point is this - Now, I am a Johnlock shipper and follow TJLC pretty closely. However, I have seen many different ship readings and I believe everyone expected a different romantic outcome to it. This backlash towards this last episode was not just because one or more groups of people were not given a “kiss” or some sort of confirmation, but because the show became too one-dimensional and complicated its plot due to extraneous factors. Were they in Moftiss’s control or not? I’m not sure. However, it was not the Sherlock we knew and loved. For that, I guess a new series would be helpful, or not. Maybe not. I’m not sure.
However, I implore you all to give Moftiss a chance to make amends. This is just a matter of poor leadership, nothing which can’t be fixed with some re-organization.