Yep, I’d just say Marissa is hopeless, and call someone who might be able (should have) to clarify her Yahoo misdeeds in detail, like Tomi Ahonen did to Elop’s in Nokia before Microsoftian acquisition. They could hire Carly Fiorina to bring some synergy to the orphaned background processes of Yahoo self-indulgence, though. And, of course, forget not about golden parachutes.
I still continue to use Yahoo mail amongst mine mailboxes, but it shows ever-worsening tendency to crash and black out, especially when uploading huge attachments. I prefer mobile version now, it became significantly more stable very soon after Yahoo Mail redesign under Marissa. Tumblr is of less significance for me.