It's funny how people keep saying this - when it's pretty far from reality.
Apple cases are proprietary.
Apple power supplies are proprietary.
Apple motherboards are proprietary
Those just happen to be the items that fail most frequently.
In addition, for the 'generic' parts, there's really no such thing as 'generic' RAM or GPU or CPU or hard disk for an OEM. Those things are purchased with specific specifications and the specs vary with the purchaser. Apple can be buying a CPU with tighter specs than Dell, for example. There is, in fact, evidence of that in that when people installed 'generic' RAM into earlier Macs, it often failed while Apple RAM worked perfectly.
The proof is in the pudding. Every time a magazine does a reliability survey, Apple at at or near the top of the list. ALWAYS. Apple is always at the top of the list for customer satisfaction.
So please stop with the 'they're all the same' nonsense.
Well, of course, I know (we all know) there are good and bad qualities of RAM chips (going back decades) the old talk about good quality memory and cheap memory.
But I did not know that Intel, ATI etc made special "higher quality than those put into PC's" CPU's and GPU's just for Apple. Wow, learn something every day.