Carl C. Icahn's battle against eBay has drawn a number of boldface names into the fray. The latest entrant happens to be one of the most prominent executives in Silicon Valley at the moment: the LinkedIn co-founder Reid Hoffman.

In an online post on — where else? — LinkedIn, Mr. Hoffman criticized his fellow billionaire for waging a battle based on short-term thinking. Spinning out PayPal from eBay or selling it outright might generate a quicker return for shareholders, he argued, but it might inhibit the payments processor from reaching its full potential.