Honestly, I'm not sure what to say...I have only been involved majorly in the series for around two years, and in those two years I have not followed the online news much until Lords of Shadow. I don't know much about the IGA vs. MercurySteam debates. Both developers are good in their own respects. It seems to me that IGA is a developer that tends to ask "what can I do next," for better or for worse. He always seems to be facing forward. I agree with some of his decisions, and at the same time, I don't agree with others. Like I said, I am relatively new to the series and I have not played every game, and have beaten less, and as I discover installments I have not played, my opinions change as I do play them and I am able to form my own image of the series. I was quite hasty to reply with "of course he won't!" when told to keep dreaming about a 2D classicvania, and I apologize for any red flags that may have raised.
One thing I have found about this series is that it is very difficult to please everyone at once. What one person loves, another is sure to hate. There does not seem to be a middle ground, but variety is the spice of life, I guess.