You can’t blame him for the failures unless you also credit him for the successes. IMO it’s very much a team effort - we’re all in it together so we take the success and failure together.
He certainly did have his part to play in some of our success, though how much of that was down to momentum is up for debate, but if he tells us that he's 100% in charge of football decisions at the club and we see 2 years of poor decision after poor decision then he's rightly going to take some stick for it.
Who have you reported this to, out of interest? Not the Saints mods, which would be the appropriate people!