When she joined yahoo in 2012, Microsoft was willing to pay $51 Billion for Yahoo thats how the valuation was, But after running it for 4 years the valuation reached a low of $5 Billion. She said she will turn it around. In 2016 she said she will turn yahoo around in 3 yrs. And very soon yahoo was sold, she misguided a lot of stockholders with that statement. Also the blame of a sinking ship goes to the captain as does the credit to the loot of a pirate ship.
If she didnt run yahoo into the ground then who did ?
I do actually want to give credit to this point. I have no strong feelings at all on Marissa/yahoo, but if you join a company as a CEO and it loses 90% of it's value, from a business perspective at the very least, you failed.
If you know the ship is sinking, then you should sell it right away (at 50B) then invest that in index funds, and end up with +7% each year, instead of -90% over 4 years.