The fact that you apparently don't understand the security implications here and the reasons why Apple is pushing for codesigning does not mean that Apple is putting up artificial barriers out of greed. That's a pretty ludicrous claim - do you really think the $99/year Apple gets from developers (who aren't already paying for iOS) even registers as a blip on their balance sheets?
The next time you see something you don't understand, your automatic reaction shouldn't be "those greedy bastards", it should be to actually educate yourself as to why it's being done. You may find that in a lot of cases there are actually really good reasons for it. And even if you decide that you don't agree with the reasons, that doesn't make it appropriate to accuse someone of being greedy or doing "evil" things (e.g. artificial technology barriers to extract money), and it's rather offensive for you to do that.
I suspect it is you that doesn't understand the security implications -- if all it takes is $99/year to gain the ability to sign arbitrary code, then there is no security benefit whatsoever. Pure security theater.
Obviously, the $99/year isn't making Apple a lot of money. But what it is doing is creating a culture of acceptance around Apple-as-gatekeeper. The iOS app store is most certainly making Apple a non-trivial amount of money (yes I know its a small percentage of their total at the moment.)
The next time you see something you don't understand, your automatic reaction shouldn't be "those greedy bastards", it should be to actually educate yourself as to why it's being done. You may find that in a lot of cases there are actually really good reasons for it. And even if you decide that you don't agree with the reasons, that doesn't make it appropriate to accuse someone of being greedy or doing "evil" things (e.g. artificial technology barriers to extract money), and it's rather offensive for you to do that.