According to the live transcript as provided by NASDAQ, Ballmer was blunt in his description of why the error was committed [Lightly edited by TechCrunch]:
“If there’s one thing I guess you would say I regret, I regret that there was a period in the early 2000s when we were so focused on what we had to do around Windows that we weren’t able to redeploy talent to the new device called the phone. That is the thing I regret the most. The time we missed is the time we were working on what became [Windows] Vista and I wish we had resources slightly differently [deployed]. It would have been better for Windows.”
If Gates was late to the Internet, Ballmer was late to phones. It’s oddly nice to hear him admit it out loud, taking responsibility for the mistake. That Vista was what cost Microsoft early aggression into phones is almost ironic.