I'm sorry, but I just don't understand this line of reasoning. How can security measures like this harm most users, especially given it's something that can easily be turned off.
And that's pretty shitty. Now a lot of people will say "it's only $99/year; what's the big deal?"
Well, first off, that's $99/year, forever, or your apps stop working. That's quite a commitment for a small developer.
Secondly, $99 is steep if you're developing freeware. You should not have to pay a hundred bucks a year for the privilege of giving your software away without people thinking that you're trying to steal credit card numbers or something.
Finally, $99 is steep for a lot of young people. I started developing freeware and shareware when I was in high school. If I had had to pay $99/year to make my app presentable, it probably would have been a deal stopper.
Now, you might say "Sure, but you're an established shareware developer and none of these things apply to you." But they still affect every shareware developer. Ever notice that nobody seems to be have been successful with shareware on Windows in many many years? Everything on that platform has been "free trials" and sketchy ad ware. The difference is ecosystem.
For many years, there was a thriving freeware and shareware ecosystem for the Mac, and so Mac users expected to be able to find freeware and shareware solutions to their problems. They expected to be able to find a handful of cheap or free programs that did what they wanted, and they'd be able to try out each one until they found one they liked. They expected this because it was true.
And free/shareware developers expected there to be an audience of Mac users looking for a free/shareware app that did what their app did. And they could be reasonably sure that if they fulfilled a real need, did it well, and kept the latest versions up on software aggregators, they'd be able to reach that audience.
But those three points above, along with the decimation of aggregators, and the introduction of the Mac App Store have broken that ecosystem. And let's be clear: Apple didn't merely sit by while the forest burned. They clear cut the damned thing and built their app store there. That thriving ecosystem had helped Apple sell computers, but it didn't profit them directly. So Apple set out to change users' expectations away from "find some cheap/free software out there written by a small developer" to "check the App Store", all so that they could squeeze 30% out of the process.
I do not think Gatekeeper is really about security. I think it is about turning the Mac App Store into the Only Way to release software. It's just a little squirt of agent orange to make sure that the forest doesn't grow back.
I hate going to random websites and giving them my credit card and dealing with whatever license key they give me.
I hate trials. Cheaper apps I can buy more liberally are nicer.
I hate crappy software that spews stuff around my system. Even though some apps can never be subject to sandboxing, I think forcing the rest to clean up their interactions with the rest of the system is an advantage of the App Store. (But I am biased in this particular opinion.)
I like having all my updates in one place.
I think the App Store generally has the potential to provide much better discoverability than the combination of Google and some crappy websites. Even considering the fee, I think that if people get used to it, the store can provide a better version of the "find some cheap/free software written by a small developer" concept.
I like that my mom is much more likely to use the App Store than VersionTracker.
I think the Store is only the death of an ecosystem insofar as it replaces it with a slightly different, but mostly just improved ecosystem.
But it's not an ecosystem now. It's a garden. And maybe it seems improved from a user's perspective, but it is completely fucked from a developer's perspective. If we can agree that Apple has made selling outside the App Store nonviable, and that dealing with the App Store is complete hell for developers, then I think we can agree that this is a bad situation for developers.