Both are equally responsible for the malaise. Maybe it is wishful thinking but I just think the situation at our club is very unique and I don't think it's a given that Wenger's successor will be given the same free reign.
I agree that Wenger's successor will almost by definition not have the unhealthy level of influence at every level that he enjoys - but given Wenger's legacy of not spending big, its difficult to see how this will change given the owner's approach to his cash cow.