As a developer, if you compare the mobile phones for Nokia and iPhone. iPhone has 2 type of hardware (iPhone and iPod Touch), 3 version of OS (may be you just need to take care the latest version). iPhone hardware has iPhone 1.0, 3G and 3GS, the later 2 are just with 3G enable and faster speed. Developer does not need to cater for different specification.
Nokia has wide range of phones from S40 series to S60 series, one or two of it has touch screen, the others do not, different screen size, button control... is complicated. I can't find my Nokia 2630 on OVI store, may be it was not supported, but the phone is just 1 year old.
Apple iTunes App Store has a close and strict strategy (as usual), because you can not install third party application without going through iTunes App Store (unless you jailbreak it). You can not simply upload an application without Apple's approval. The Google voice case is a good example, FCC step in and invest for the case.
Everyone is criticizing on Apple's strategy for its iTunes App Store, but all vendors are following Apple model and marketing plan. Google has Android Market, Microsoft has Windows Mobile Market, Palm has App catalog (for WebOS) and Nokia has OVI store.
OVI website. Not just the concept. The design looks like Apple website.
(The menu and navigation bar)
Palm OS is very successfully mobile platform without an application store, you can download third party application from other website like handango. It fails because Palm does not provide a stable software and good service.
iTunes is available on Mac and PC. Nokia has a good desktop application call PC Suite, and it only runs on PC. When Nokia will have a Mac Suite or Linux Suite? Nokia OVI Suite is the next version of Nokia PC Suite, which expected to have a Mac version, but not sure when it will be released.
Why follow Apple if you can not beat Apple. At the end, not everyone like Apple, right?