GameStop (NYSE: GME) CEO Ryan Cohen has publicly attacked eBay’s (NASDAQ: EBAY) leadership after the e-commerce giant’s board rejected his $56 billion unsolicited takeover proposal. eBay’s board dismissed the cash-and-stock offer as “neither credible nor attractive,” raising serious doubts about the financing structure behind the bid. GameStop proposed to acquire all of eBay’s common stock at $125.00 per share, split evenly between 50% cash and …