[plinkplonk]

"the industry notion that a CS degree is needed to be a good engineer needs to be challenged."

true enough. but whether CS knowledge is required is a more interesting question. John Carmack (picking a name from your 'homegrown' list) is extremely knowledgable about algorithms, computer architecture, graphics etc.

of course, it also depends on the definition of 'good engineer'. If you define it as "someone who can build a simple CRUD app in Ruby on Rails", then probably very little CS knowledge is required.