You're correct in saying that Jobs isn't criticized for missing enterprise software. He is criticized for trying to break into it and doing a terrible job of it though. Remember the XServe? Fortunately, he had the good sense to can that eventually.
Unfortunately, MS doesn't seem to be as introspective. I agree that it's best to see MS focus on their enterprise products. That requires them to... well... focus on their enterprise products rather than continuing their half-assed attempts to make consumer products.
Everything Microsoft does is about the domination of Windows and Office. These are their big moneymakers and they don't want to give them up. Are you sure that a royalty of $50 for practically every single PC manufactured in copyright-observing nations is worth less than their enterprise software? What about everyone that goes out and spends $100+ on a copy of Office? Those are some big markets and I'm not sure their value is so diminutive.
Additionally, such a platform allows tight integration of things like .NET, attracting developers to Windows' platform and allowing MS to sell dev tools and servers. Would .NET be worth less if Microsoft's desktop share were diminished? Almost definitely, imo.
Please don't underestimate the value of desktop dominance.
Well, Jobs is not criticized for failing to break into enterprise software because he has had outrageously, unprecedentedly, massive success breaking into other markets. Failure is perfectly tolerable when you are good at something. Ballmer is an all around failure, and there are thousands of better candidates for his position.
I should hope to be such a failure. He served as the development manager for the original MS Windows, one of the greatest business franchises of all times. During his tenure as CEO he's taken what was already a mega-cap company and more than doubled their net income and tripled revenue.
And clearly the market seems blase - if you improve your top and bottom line and your valuation gets cut in half, that generally means investors don't think your future is all that bright.
Unfortunately, MS doesn't seem to be as introspective. I agree that it's best to see MS focus on their enterprise products. That requires them to... well... focus on their enterprise products rather than continuing their half-assed attempts to make consumer products.