Sorry, but that's an excuse.  They could have spoken up earlier, just as they are speaking up now.  The question is why speak up now and not then?  Is it because they weren't willing to risk their fame and fortune to do the right thing? Is it because they were willing to watch others suffer the same abuse while they prospered in Hollywood?  If they knew and stayed quiet while others were abused, then they are also complicit in those crimes.