Uhm, Apple does actually provide easy root shell access to what is essentially Unix.
And the APIs to customize your desktop experience are much more permissive than what Windows allows. Or at least the Desktop customization apps do much more than their windows equivalents.
I'd say that having usable defaults is better than having easy customization. People who customize to that level don't care about it being "easy"(myself included).
Apple's culture and ecosystem is restrictive. I think when they created iOS it was a natural fit to lock that shit down. However I will say that OS X remains fairly open, likely because it was created before Apple's culture shifted into playing parent (which is arguably a response to Windows XP's continual security problems).
Now, yes, people will point out that OS X only runs on Apple's hardware and that is restrictive. However as a counterpoint I will say that OS X is free and it would be uneconomical without that tie-in. That's their business model effectively.
And the APIs to customize your desktop experience are much more permissive than what Windows allows. Or at least the Desktop customization apps do much more than their windows equivalents.
I'd say that having usable defaults is better than having easy customization. People who customize to that level don't care about it being "easy"(myself included).