What would happen to linux if it was undergoing the kind of thorough examination that windows does? Wouldn't people still find holes/bugs to write malware for?

Microsoft is in crisis, and crises sometimes demand bold action. The company is demoralized, and most assuredly HAS seen its best days in terms of market dominance. In short, being Microsoft isn't fun anymore, which probably means that being Bill Gates isn't fun anymore, either. But that, alone, is not reason enough for Gates to leave. Whether he instigated the change or someone else did, Gates had no choice but to take this action to support the value of his own Microsoft shares.

Let me explain through an illustration. Here's how Jeff Angus described Microsoft in an earlier age in his brilliant business book, Managing by Baseball:

"When I worked for a few years at Microsoft Corporation in the early '80s, the company had no decision-making rules whatsoever. Almost none of its managers had management training, and few had even a shred of management aptitude. When it came to what looked like less important decisions, most just guessed. When it came to the more important ones, they typically tried to model their choices on powerful people above them in the hierarchy. Almost nothing operational was written down...The tragedy wasn't that so many poor decisions got made -- as a functional monopoly, Microsoft had the cash flow to insulate itself from the most severe consequences -- but that no one cared to track and codify past failures as a way to help managers create guidelines of paths to follow and avoid."

Fine, you say, but that was Microsoft more than 20 years ago. How about today?

Nothing has changed except that the company is 10 times bigger, which means it is 10 times more screwed-up.