Richard Murray has explained why he stayed on as non-executive chairman of the Charlton board. He only wanted to make things better and exert influence from within: Richard Murray
Quite what the results of that influence have been, it is hard to tell. The fan sofa perhaps?
I think that it is very sad that someone who contributed so much to the club in the past, and whom I and many fans respected, has become an apologist for the current regime.
My purely speculative take on what happened is this. Under the former owners, the club was close to going into administration. Along comes Roland offering a lifeline. He seems a bit eccentric, but he has the readies. It takes a while before Murray realises what the downside is, and by then he is in too deep.
A Murray resignation would have probably shaken the regime more than anything else.