DW largely overcame Grade back in the 80s. (Although, Grade, Powell, and others certainly didn't do anything positive to help.) It was apathy that killed Who. No one had the time or energy to revitalize an aging, difficult to make series, that was losing viewers. Producers just didn't want to take that on.Plus you have to consider the Beeb itself. Is someone an active hater of DW, ala Michael Grade?
I'm seeing the same pattern now. No Grade like figure I know of, but the same apathy to revitalize a declining, complex series.