I'm pretty sure that the Symbian Signed initiative was launched a number of years before the iPhone was announced and both RIM and Qualcomm have had paid app signing for the Blackberry and BREW platforms respectively for even longer.
While there's much to criticise about Apple's approach with the App Store, I don't think it was unreasonable to require app signing and a developer fee in return for getting your apps hosted and easily available on the App Store. I would prefer it if there was also an alternative distribution mechanism available, but that aside I don't have any problem with the App Store as a concept.
You are right, Symbian Signed was launched in 2005, it was new feature in Symbian 9/Series60 v3.
The difference was, that Symbian Signed aimed for accountability - they wanted to trace back, who made which binary. They didn't really cared what the binary did, just in case of malware, there was accountability. You got your certificate upfront and in 99% cases, they didn't care what you are going to write and how you intend to distribute it. The rest 1% (still hugely inflated number) was, when you requested root-like capabilities (i.e. you would have a way to mess with hardware or DRM directly), then they wanted to hear your business case.
BREW platform was, to put it bluntly, non-player on non-market (US was at the time considered backward contry mobile-wise and the rest of the world ignored BREW). RIM was never popular among third-party developers, and among users everyone was buying BB for the messaging, nobody cared for third-party apps.
I do have problem with Apple's approach with the App Store. I think it is unreasonable to be bridge-watching troll between me and my device. IF there was a way to sideload unsigned or self-signed binaries, that would be not a problem, but App Store is the only way to put app on the device, and this way is gated. If the App Store was optional (althrough still preferred or popular) way, I would not have problem with paying for hosting and cataloging apps.
While there's much to criticise about Apple's approach with the App Store, I don't think it was unreasonable to require app signing and a developer fee in return for getting your apps hosted and easily available on the App Store. I would prefer it if there was also an alternative distribution mechanism available, but that aside I don't have any problem with the App Store as a concept.