Well, obviously not just Apple, but Apple in particular.
Apple has chosen to ship new 15-inch MacBook Pro models with last year's (Haswell) processors, because the appropriate low-power, quad-core chips remain unavailable in the current generation (Broadwell) of Intel processors. With the first of the next generation (Skylake) processors arriving in August, it's likely that, for this particular product line, Apple will skip Broadwell altogether, and, once new MBPs ship with Skylake, all will be well once again, for awhile.
Meanwhile, ARM cores and Apple's implementations of them are closing in on the performance levels of Intel's products, while continuing to beat the pants off of Intel in terms of performance-per-watt, although Intel has made progress in that regard.
If current trends continue, at some point it won't make sense for Apple to continue to use Intel processors for some Mac line, probably beginning with the 12-inch MacBook or MacBook Airs, but once one line switches over, the others will surely follow, with the Mac Pro being the last holdout.
When that day comes, it's likely there won't be many tears shed at Apple.