Megan Fox told Italian publication Amica that the decision to remove her Marilyn Monroe tattoo was made due to Monroe suffering from personality disorders and she didn't need that kind of negative energy in her life. Presumably, she just became armed with this knowledge. Fox must think that Monroe's spirit lived-on inside that tattoo and it, not her terrible acting, is what caused her to suck the life out of so many movies.
According to Amica:
What is happening to your Marilyn?
I'm removing it. It is a negative character, as she suffered from personality disorders and was bipolar. I do not want to attract this kind of negative energy in my life.
Times like these you wish you could dig up a corpse and get it's perspective on the situation.