The implication of your post (if I understand you) is disturbing. You seem to be saying that Apple's failure to innovate ALL the technology it uses is proof that it innovates nothing. I don't know anyone -- not even the greatest champion of Apple -- who suggests that Apple has innovated every technology it uses. Indeed, NO company can make that claim; and it's a preposterous standard to hold a company to. So, yes, you rightly point out some examples where Apple took the ideas of others and implemented them on the Mac platform. But what would you have Apple do? Would you have it use ONLY those technologies it creates in house? If it did that, then Apple would again be criticized for the "Not invented here" mentality.
Can you spell "No win"?
From my point of view, Apple strikes the right balance between innovation and making the most of existing technology. Apple's innovations include Open Doc, Rendezvous, Firewire (in conjunction with other parties), Truetype font architecture, ColorSync, and many other things. Apple was also a first adopter or one of the first on many other technologies. After all, there is value not only in innovation but also in implementation.
Does Apple borrow some good ideas from other sources? Yes. Does this preclude any innovation of its own? Does it snuff out third-party development? No -- on both counts. These things are not mutually exclusive. So I'm sorry, but I really don't know what point you are trying to make. If it's that Apple is not innovative -- and if your "proof" consists in such things as contextual menus and Sherlock, I'm afraid your logic escapes me.
As for encouraging development, I think we need to recalibrate our expectations of what is fundamental to computer operation (and thus rightly within the domain of a computer company) and what in contrast falls outside that domain. Font management is not a luxury to an OS -- especially not to a platform which serves the graphics niche market. The only reason that third parties developed font management utilities is that in the early years of desktop personal computing, such things were slow in coming from the OS developers themselves. (They had their hands full with other things.) But as the technology matures, these things are becoming more integrated, as they should.
Do you remember the days when third party developers offered file search utilities? Do you think it's realistic that a computer company like Apple should leave this "market" wide open in the name of "encouraging developers"? Do you not think that to search for a file is fundamental to the OS? Well, the same goes for other software that once was a rich source for independent developers -- including disk diag/repair tools, file managers, browsers, batch renamers, archivers and compression tools, and many other things. People have higher expectations today of an OS. I, for one, do not wish to be at the mercy of independent developers for functions as basic as contextual menus or managing my fonts. If developers wish to do Apple one better in these areas -- more power to them. But I don't begrudge Apple one instant for its choice to integrate these things into the OSX package.