Some might argue that this is a moot point given you have to purchase an iPhone or an Android based handset to notice this first stage, but I'd counter argue that there's a 14 day return policy in the UK for a reason. Surprisingly then, given the two platforms are firmly consumer focused, neither gets off to the best start and it's their steadfast refusal to break from their preferred partners that's the problem.
With mobile OS X the stumbling block is obvious: iTunes. Love or loathe this software the simple fact of the matter is that Apple gives users no choice about whether to use it or not and before you can even try out a shiny new iPhone the first port of call is hooking up to a PC with iTunes (and often a latest version at that) and registering your handset. If you don't already have an iTunes account this can be a lengthy and boring process and the fact it then ties your handset to a single PC (unless you plan to sync different aspects of your handset separately, ie: media from a desktop and email, calendar and contacts from a laptop) only makes the system more frustrating.
To be fair Android isn't much better. In buying an Android phone it is probably safe to assume you have a passing interest in Google's existing services but having to own a Google account just to get to the home screen is ridiculous.
Naturally, like mobile OS X, doing things the company's way has benefits (Google will automatically sync mail, contacts and calendar entries) but as Android is also happy to accept most other forms of mail (excluding Exchange - more on this later) this seems to border on the ridiculous. Furthermore, for an 'open' platform the whole scenario is completely out of character.
A bad start for both, so let's move on.