TI's reasoning is that they don't want to be sued because someone designed, say, a fly-by-wire control system which uses COTS MSP430 parts, and then accidentally built one with a bogus MSP that went toes-up on final and brought a jetliner down short of the runway. It's not that they are averse to their parts being used in life-critical applications; it's that they have specific lines for that purpose, consisting of parts which have undergone much heavier and more stringent testing as compared to the general-purpose lines, and if a designer of life-critical hardware can't be bothered to get in touch with TI and arrange to source parts from one of those lines, then TI's not going to be held responsible for a bad result -- nor should they.
I dare say Apple's reasoning is similar. It's not that they actually expect (e.g.) iTunes to comprise a critical component of a nuclear weapon's operating software, inasmuch as such a device has any; rather, it's that if someone does for some lunatic reason actually build an iTunes module which happens to set off a 1Kt IND when you play the same Lady Gaga track ten times in a row, Apple's not going to be held responsible. Granted, it's a particularly stupid and pointless example of gratuitous lawyerese, but the underlying reasoning is probably very similar to TI's. (Although I do rather doubt that Apple makes a special version of iTunes which is certified for nuclear-weapons use.)