That’s already pretty good in my opinion, albeit if only for the cases where it works. It saves you the trouble of declaring the loop counters, and you can always replace a scalar with an array if need be. The part I find the most restrictive is you can’t use them as callback functions.
Does that really have to do with the language standard? In my eyes it’s just the (poor) choice of one vendor to put temporary array expressions on the stack. The language itself has no notion of stack or heap. The only place it alludes to the existence of a heap is in the section on runtime environments (J3/18-007r1, C.12.1), where it says that:
heap allocation/deallocation (e.g., (DE)ALLOCATE in a Fortran subprogram and malloc/free in a C func-6
tion) can be performed without interference