Android beat iOS is market share a long time ago. Over all I think Android phones out sell iPhones 2:1.
Android is probably the more numerous still but the gap is probably much closer than the sales suggest.
But this doesn't mean that good 2nd hand Android devices don't get passed on to family or friends. All the devices in my family whether iOS or Android get passed along. The Android handsets are perfectly fine.
Apple is enforcing application signatures on the Mac because it's the Right Thing To Do security-wise. Rather than get stuck in a monthly patch-churn cycle like Microsoft is, endlessly releasing Windows fixes for all the sieve-like security holes in every last system library in their OS, Apple is choosing a better, safer, saner way. Vet all the third-party code that runs on the system, or at least force a certificate trail back to abusive or unscrupulous developers.
If you want to run untrusted software on OS X, good for you. Turn off GateKeeper. But requiring developer signatures on native executable code as the default makes too much sense. Arguing otherwise, when there's an easy way for 'power users' to turn off the protection, is elevating the rights of the lazy developer to distribute their code however they like over the rights of non-technical users to enjoy an uncomprimised computer.
Not sure what to think about signed apps, I just reject the App Store model. Whether it will become the only way in future OS X versions only time will tell.
I just went through signing the app that my company makes (even though, as yet, we don't need to sign because of the way we distribute). It took me the better part of a week to figure it out (mostly because I did something silly in my script), but I now have several scripts that I can use to make sure our next product is signed out of the gate.
Long-time Apple supporters will tell you that Apple is (a) not requiring all apps be bought from the App store and (b) that they are making mistakes with the sandboxing entitlements that are available, causing apps to leave the App store. In my experience, die-hard anti-Apple folks (like you seem to be) prefer to distort and ignore.
Apps leaving the App store - we'll see how that will play out. Who still develops apps for "classcial" computers anyway?
And by default, you can simply hold down a shortcut key to open an application and install it anyway without a signature.
As for the shortcut keys, I can never remember them.
As for the shortcut keys, they're documented, so you don't have to remember them.
As far as who develops apps for "classical" computers…there's a lot of us out there, because they're not going away.