Does anyone want to see a TMNT world without Leo, Raph, Mikey or Donnatello? Everyone knows The Ghostbusters accordingly to their characters. The success was extremely dependent on not only the actors but the 4 character names with it's fan base/pop culture throughout 30 years. It was pretty much successful throughout besides Extreme Ghostbusters. That was really the only time they ditched most the crew.
If this was a full on Ghostbusters 3 being helmed by Miller and Lord with a cast featuring actors like Pratt, Emma Stone, Kristen Wigg, Anthony Mackie, Rose Byrne or Bill Hader. With Ray and Winston returning, people would be pretty stoked. There would not be a quarter of the complaints or worries. Likewise if it was a reboot but they recast Venkman and Stanz with some new characters. If they want the franchise to last for another 30 years recasts have to take place at some point. Even if only Ray passed the torch to this new crew Feig is in control of I think things would be more positve. They won't lose points for that, and he can still make his own modern version. Basically just anything to have a connection character wise other then these are people who hunt ghosts.
Not saying it can't work. I just don't see the point in axing everything out on what people like. This is killing the main characters who are the only Ghostbusters we know completely out of the picture. Usually studios market the main selling characters one way or another. It's actually the opposite of what you should do. The reboots of the 80s have not gone very well as it is and this is one of the biggest and recognizable of the time. People are gonna expect alot, which makes it easier to be let down. Why not give the fan base and audience just a bit of what they want? Which is really just respect for the characters that made everything about this franchise.