I think a lot of this is more that apple doesn't give a damn about reuseability, they care about perfection. If the promo after father's day has an image that goes over the border by 3px, they'll write it from scratch.
http://www.ifixit.com/Teardown/MacBook+Pro+15-Inch+Retina+Di...
Similarly, the filesystem on OS X. As far at the Mac parts go, while the BSD folders have visibility toggled off.
All I did say is that they absolutely do _care_ about what's below the surface. Parts that a fraction of a fraction of folks will ever see are given loving attention far beyond the norm. Do most or any other manufacturers color coordinate battery warning labels, PCBs, etc., down to the cm^2 headphone jack?
iOS's WiFi still hasn't fixed the basic usability bugs I reported against 1.0 (simple things like “Don't capture the UI until the hotspot page has actually loaded” or “Don't nag me asking to reconnect to a marginal network I already requested you connect to”).
iOS autocomplete remains an embarrassment, frequently turning correct words into nonsense or failing to handle minor inconsistencies in input which didn't produce a valid word.
iOS backups don't backup the stuff you care about like passwords or settings but do backup things you can trivially re-download from the store like apps. This is not in any way documented and the backup status will simply claim the backup was successful without mentioning that it includes almost nothing important.
FileVault had data-loss bugs for multiple releases until v2 was released. Time Machine still doesn't check data integrity and the remaining users complain about weird UI bugs, performance impact, hangs & data loss, etc. Nobody at Apple appears to care.
iCloud sync is a disaster with uncontrollable delays and hangs (e.g. http://createlivelove.com/246). There's no sign of anyone at Apple caring since it hasn't impacted iPhone/iPad sales.
To reiterate: Apple doesn't obsess about quality unless it's needed to get people to buy the device.