Snowflake,I also agree that she should be deciding on weather she wants to stay in the mairrage altogether, not just saving it for the sake of what other people think.
My only guess as to why Iyanla won't give any blame to Lisa's husband is because Lisa has done enough blaming. I think if you gave her an inch, she'd take a mile. Him cheating was his fault but her dealing with it all these years, in a negative way, was her fault.
This is just me but I can not imagine staying in a mairrage when she was so resentful. Nevermind how it looks, she wasted a looooong time. I think to a point everyone cares what other people think but that's just rediculous (understatement).