We've been using it for over a decade (small part of a major defense company). We do not (and have never) targeted any Apple operating systems.
We never ran any NeXT machines. There was no (and frequently continues to be, thankfully - we've got some good negotiators who manage to convince the customer that picking the language themselves is often not smart) customer requirement on language. As I recall, a number of candidate languages were examined as a replacement for C (which was what we were mostly using at the time) and the lightness of Obj-C, its Smalltalk-like object model and the ease of training newcomers to go from C to Obj-C, were amongst the reasons.
Outside of Apple and the few examples I haven't met anyone who has decided that objC was an obvious choice.