I heard on the radio this morning that it was the "actors" who objected to Mr. Gibson. Note the plural.
A sequel can be made without the same director, writer or producer, but it very difficult not to have the original stars.
Even B list actors have collective clout. Factor in their agents, and the clout is much larger.
Mr. Gibson could take his multi-millions and return to Australia and make (and finance) a host of small-budget films for the rest of his life and probably make money.
Watching anyone commit career suicide is disturbing, but here is a famous and powerful man who knew his limitations and yet still did not seek help to avoid situations. Mel Gibson has been at AA meetings over the years. Friends had seen him in NYC, so I must assume that he attended in LA as well. He has had a massive and self-destructive slip. He is very lucky that he has money to cushion his fall.
Nobody wins.
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher